Previous:	Peak 15 Containment Breach Armstrong cluster campaign Skirmishes in the Aleutsk valley
Concurrent:	Battle of Virmire (Phase I)
Next:	Battle of Virmire (Phase II)
Battle of Peak 15 Part of the Eden Prime War
Peak 15 during the battle
Date:	7 July 2183 CE
Location:	Peak 15 / Noveria / Pax, Horse Head Nebula
Outcome:	Tactical Alliance victory Benezia M'Soni breaks through Saren's indoctrination before dying Saren's asari commandos are wiped out Location of Mu Relay determined Rachni queen freed Rachni outbreak contained and all rachni within facility purged Saren's Alliance loses its intended rachni army
Belligerents Systems Alliance Supported by: Cerberus (independently involved as part of Operation: Black Light) Saren's Alliance Geth Heretics Elanus Risk Control Services Rachni Commanders Marcus L. Shepard Jacob Taylor Benezia M'Soni † Herau I'Loak † Romero Ventralis † None Strength Normandy Squad 7 combatants 1 M35 Mako 4th Assault Squad 13 Cerberus commandos 23rd Commando Company 60 asari commandos Geth Heretic Army 90 geth troopers (latter half of the incident) 8 geth destroyers (latter half of the incident) 5 geth assault drones 5 geth armatures 1 geth prime Elanus Risk Control Services 75 security personnel Roughly 10,000 rachni workers Roughly 3,000 rachni soldiers 4 or 5 rachni brood warriors Casualties All Cerberus commandos except Jacob Taylor are killed Geth heretic forces wiped out 23rd Commando Company wiped out Matriarch Benezia M'Soni killed Major Herau I'Loak killed Captain Romero Ventralis killed Remaining ERCS personnel killed All rachni purged

"Code Blue has been declared at the Peak 15 facility. We don't know what's going on over there, but whatever it is...let's hope the cold kills whatever they cooked up."

— Maeko Matsuo.

The Battle of Peak 15 was a medium-scale military engagement between the rachni, ERCS, forces of Saren's alliance, a squad of Cerberus commandos and a small team of Systems Alliance personnel. Following a containment breach at Peak 15, where rachni escaped containment and briefly engaged ERCS security forces, Cerberus commandos led by Jacob Taylor, quickly followed by geth and asari commandos led by Matriarch Benezia, arrived to investigate the situation. The battle begun upon the arrival of the Normandy squad, who had come for Matriarch Benezia.