Ventralis is manning the Rift Station perimeter against the rachni continually coming along the tram tunnels. As he explains, he and his men have been on guard for several days, and are exhausted, taking stims to stay awake. A group of attacking rachni interrupt him as he is speaking—Shepard is puzzled as to why they keep attacking the position, as it is a natural kill zone, but Ventralis cannot explain it. He talks briefly about the facility and the situation, but he does not know much about the labs themselves. He warns Shepard not to poke around in corners, referring to the sealed maintenance area.
When asked about Matriarch Benezia, Ventralis says the matriarch is in the hot labs, and gives a pass to Shepard so the Commander can access them. He can also give Shepard permission to go into the quarantined lab to develop a biotoxin cure for the sick scientists, with a warning that Shepard's squad must be scanned before they are allowed to leave. Shepard can return and tell Ventralis about the attack by Alestia Iallis in the quarantined lab. Ventralis is shocked that "just another egghead" turned out to be an asari commando.
If Shepard goes straight to the hot labs looking for Benezia, only to be mobbed by rachni soldiers, the team will return to find Ventralis' post deserted. Ventralis is waiting for Shepard in the barracks. He apologises, saying he is under Benezia's orders, and that he sent Shepard and the squad to the hot labs in the hope that the rachni would kill them. He then opens fire and is killed.
If Shepard breaks into the Restricted Area, the drones and the guards become hostile and attack the squad. Shepard can go back to Ventralis's post and kill him.
- Captain Ventralis is voiced by Chris Edgerly.
- Unlike other members of Elanus Risk Control Services, who wear the ERCS light-weight model of Guardian Armor, Ventralis wears the medium-weight model of Explorer Armor, produced by Devlon Industries.
- One of his responses, "...My men know the rule: Two legs good, four legs bad," is a reference to George Orwell's Animal Farm.
- When the crew is attacked by rachni upon meeting Ventralis, it is possible to abandon the situation. When you come back, Ventralis will give different dialogue, expressing distaste.