Milque is a member of Delta Squad, a special forces unit of the Alliance deployed to Fehl Prime in 2185. A talented sniper who takes down marks with ruthless efficiency, he is the team's resident sharpshooter when equipped with the M-92 Mantis sniper rifle. He is a cautious, cynical person, often giving others the impression he's a coward, although he follows orders obediently once they're given and is dedicated to watching his teammates' back - usually in exchange for free drinks after.
Milque arrives at Fehl Prime with the rest of his team in 2183. A snarker with a dry sense of humor, he comments that whatever else happens on the planet it can't possibly be worse than seeing Essex get rejected by Kamille for the umpteenth time. Essex, recovering from the embarrassment, tries mocking James Vega about his slavish devotion to Shepard, causing Milque and Kamille to burst out laughing. The friendly banter among squadmates is soon stowed away when the CO Captain Toni arrives to deliver the mission briefing.
The colony is under attack from Blood Pack mercenaries, and the squad is deployed to stop them. Milque's unit is shot down by the invaders while making a strafing run from the Kodiak drop shuttle. The survivors are rallied by Lieutenant Vega, who assumes command after Captain Toni is incapacitated.
While planning the counter-attack, Vega asks for Milque's power cells which left the sniper bereft of shields. Milque is hesitant but complies after learning the plan. He then takes position behind a rock outcropping and covers Vega while the Lieutenant charges down the battlefield at the Krogan Battlemaster Archuk.
Picking off targets with alarming accuracy, he soon gets the attention of Brood, who evades Milque's shots and returns fire, grazing him across the collarbone. Milque spews blood and is temporarily incapacitated, but is able to return to the fight just in time to blow Archuk's head off and save Vega. Asking if Vega's alright, Milque announces that the next drink's on the big guy. Sniping a krogan behind Essex later, Milque now declares that the deed should net him free drinks for life. He is commended for his actions when the Blood Pack is defeated and concedes that he is happy to be wrong for doubting the Lieutenant.
Two years later, Fehl Prime has recovered and the Alliance has bolstered the colony's defenses with a heavy anti-ship cannon and military-grade kinetic barriers. Bored at the lack of action in the last two years, Milque sardonically comments on the lack of directives from the Alliance about the spate of colony disappearances, asserting that the Delta squad "grunts" have to read between the lines and figure out the reason for the big gun. Meanwhile, he gets to tease Nicky as a "kiss-ass" for persistently referring to Vega as "sir" despite being told not to. Milque also keenly follows Vega's attempts at making his feelings known to Treeya, snidely commenting whenever Vega fails dismally.
One day, Captain Toni orders the Delta Squad to investigate a strange jamming signal originating from the colony's outskirts. At the signal's location Vega orders Nicky to find a spot for Milque to dig in, which results in the sniper and the tech talking and concluding correctly at the same time that Milque should perch at a nearby hill.
The squad discovers an unknown alien device as the signal's cause; Milque readies himself from the hill, covering Vega and Nicky who went near the artifact for a closer look. Looking with his scope, Milque determines that the artifact didn't fall out of the sky as the crater surrounding it is too small for a re-entry impact. Vega decides it is safest to destroy it and Essex complies with his biotics, much to Treeya's chagrin. Milque's warning saves Treeya, who rushed forward in agitation and almost falls into an abyss. While Treeya tries to salvage useful data from the remains of the artifact, the colony comes under attack from an unknown alien force.
Vega assumes command once more in the absence of Captain Toni. Knowing only that a huge ship appeared out of nowhere above the colony, the Lieutenant gives the order to return back. From a hidden vantage point, Milque scopes out the aliens with his sniper rifle, and the squad determines that they aren't on Fehl Prime for a social visit judging by the fact they're all carrying weapons and that their ship appears to be based on the same technology as the artifact the squad found in the ruins.
With little else known about the insectoid invaders, Vega resolves to assume the alien arrivals as hostile and directs the squad to go in stealth for recon. Milque suggests that maybe "someone" should stay back for lookout and guard the Mako they were using for transport. Vega doesn't answer and Kamille remarks that maybe "someone" needs to grow a pair.
When the squad finally learns that the invaders were harvesting the colonists and taking them up to the ship, Vega cooks up a plan of rescue. Mason and Milque provide distraction and sniper backup, respectively, while the rest go with James to the colony's newly-installed defense cannons and try to disable the ship. Vega tells Milque that he's counting on the sniper to watch their backs and Milque replies that for once he'd like someone to watch his back instead. Regardless, Milque takes up his assignment in a vantage point overlooking the squad's entry route.
The cannon fails to penetrate the ship's kinetic barriers, being fired only at half power. The alien ship's eye defense destroys the cannon and hostile troops start attacking the squad. Milque is taken off-guard by a trooper who sneaks up quietly beside him. He is saved by the timely arrival of Mason, who sabotaged the fuel depots earlier to draw off the aliens from the defense tower. Together they fight their way through the invaders and reach the underground labs in a tram, causing a cave-in and sealing off the aliens' approach route.
Once inside the labs, the team tries to revive Essex who was incapacitated while holding off the enemy swarms. While searching for potential cures in the lab's databases, Nicky stumbles upon a file that reveals Messner, the owner of the Mako they used earlier, is a Cerberus informant. Messner reveals that the alien force they were fighting are called Collectors and that these Collectors are responsible for the human colonies disappearing in the Terminus Systems. The group's ruminations are cut short by a disturbance emanating from downstairs, and Vega takes Mason and Milque with him to investigate.
It turns out that Brood was never shipped out of Fehl Prime. Milque and company find the krogan imprisoned in a tank, claiming he was being used as a test subject instead because it was "safer" than transporting him back to the Citadel. The krogan offers a deal: let him out, and he can get the squad out of the planet in return. Milque, James and Mason angrily refuse and decide to let him remain there for the moment.
Nicky finally discovers a potential antidote for Essex's ailment within the science files. They try administering the cure to Essex but another disturbance interrupts their actions. Milque thinks the krogan doesn't know when to give up but Messner comes in and informs the group that it's apparently another threat entirely.
Vega, Mason and Milque take positions near the lab's entrance, and soon enough the door is destroyed, revealing a Praetorian. This Praetorian initially has its head open, revealing a mass of skulls and Kamille's upper torso. Mason gets incinerated for letting his guard down, forcing Vega and Milque to retreat. Everyone but Essex escapes through another way in the labs, with Vega and Milque laying down cover fire against the Praetorian. On the way out they take Brood with them in exchange for the krogan's cooperation and ship.
The Praetorian proves to be a tenacious adversary and manages to catch up with the group while they're escaping in Brood's ship. Vega, Milque and Nicky try their best in fending off the creature, with Milque firing his Mantis at full auto. Nicky gets stabbed in the gut but soon after a cured Essex arrives to save the day, paralyzing the Praetorian while Vega proceeds to destroy it.
Milque poses an open question about the group's next move as Brood's ship is being repaired, pointing out they'll be lucky to even get off the ground with the ship's condition. Brood replies that the ship can fly alright, but can't make any promises as to how far it'll go. Milque asks if it can at least go as far as the old ruins and Essex replies that the Collector ship can still shoot them down no matter how far they run. Vega makes up his mind and proceeds to tell the others about his plan.
Vega decides to take the fight to the Collectors using the original plan: disable the ship's engines, but from the inside. Milque's pessimism gets the better of him, stating that to do so would be suicide and they'll get nowhere near the ship before "the creepy eye thing" destroys theirs. Brood makes a surprising suggestion that Vega seriously takes into consideration, and the meeting is concluded with everyone taking a swig from Vega's drink flask. Milque gets his turn after most of the group does, insisting that it's still suicide to do so and that it'll take more than a drink to change his mind. Vega replies that although Milque's right about everything so far he's about due for being wrong for a change.
Brood then pilots his ship towards the Collector ship, blasts a hole in its side, and guesses his way toward the drive core. Armed with heavy weapons from Brood's personal armory, Milque along with the others defends Brood's ship from Collector drones, selecting an M-622 Avalanche himself and partnering with Essex at the port side. Before Brood can take out the drive core, however, Messner shoots him in the head. Without its pilot, Brood's ship crashes and the group is taken prisoner by the Collectors.
After Messner forces Treeya away for his own nefarious intentions, Vega recovers from seeker plague stasis, taking out the lone guard and rushing over to the dying Brood moments before the krogan passes away. Essex and Milque show up soon after, inspecting their belongings and finding out that they're essentially weaponless. With both wondering why they recovered, Vega reveals that he spiked the drink they took earlier with the cure. Milque reacts indignantly but Vega counters that it seemed like a good idea at the time.
Vega reiterates the plan: get the colonists then get out. Milque asks if he really thinks it's going to be that easy and Vega responds with an elaboration. Milque picks up on the details and they set about getting to work using the Collectors' processing systems to synthesize more antidote and disperse it to the civilians. Since the Collector ship is already in space, Milque poses the question of how they were actually going to escape after everyone wakes up. Vega doesn't answer, distracted after seeing April's pod.
The task complete, the trio board a floating Collector platform and use Treeya's omni-tool locator signal to trace her position. By sheer luck they encounter a spaceworthy freighter along the way and Vega, remembering how Milque started in the pilots' program but washed out for having terrible flying skills, instructs the sniper to prep the freighter for launch. Milque predictably objects, but there's little choice in the matter and complies. As a final caveat, he declares that if he actually pulls it off free drinks for life aren't even going to cover the price of his compliance.
Milque pilots the freighter to the site of a battle between Vega and the Collectors at the heart of the Collector ship. Just when Vega is about to be overwhelmed by the Collectors, Milque opens fire and clears the area of Collector forces. Meanwhile, the Collector ship starts descending into the planet's atmosphere as its drive core is disabled. However, the pod containing Treeya that was vented into space earlier starts descending into the atmosphere as well.
After Vega hops aboard the freighter, he orders Milque to head for the now-awakened colonists and pick up Treeya afterwards. Treeya counters that there's no time and that James only has enough to save one or the other. The asari obtained valuable intel about the Collectors earlier, further complicating Vega's thought processes. Milque is indecisive, deferring to whatever choice Vega makes, although frantically urging the Lieutenant to make up his mind before it's too late to save either.
Flash forward to the Citadel, Vega just finished giving his report to Anderson and Admiral Hackett and is given a commendation and a promotion for his actions on Fehl Prime along with a set of new orders. Milque, curious, asks the big man what else he got, snatching Vega's orders from him, and learns that the Lieutenant Commander just got an invitation to the N7 program. Milque comments that now the big man is definitely in the league of Commander Shepard. Vega, who has been mentally scarred by the events, thanks Milque but says he doesn't deserve it. Milque is embarrassed at speaking out of turn and asserts that he is ready to follow Vega anywhere. Milque accompanies the Lieutenant Commander back to Fehl Prime, where Vega flashes back to the critical juncture in his life that led to his present state.
Back aboard the freighter, Milque asks James what to do, with time running out fast and both Treeya and the colonists' lives in jeopardy. Vega snatches the controls from Milque, steering the ship towards Treeya's pod and the intel she got. Milque is horrified at seeing the Collector ship carrying all the colonists on board burn; everyone killed in a powerful explosion as the ship impacts the surface. At the time, he judged Vega has made the wrong choice.
Milque later joins Vega and Treeya at the Memorial Monument on Fehl Prime dedicated to all of its lost souls, paying homage to the fallen.