Part 1

E1

It’s peacetime in the Gulf of Mexico, so why is the USS Pennsylvania running weapons drills?

Part 2

E2

A man’s dead. Something’s going on. Something bad.

Part 3

E3

Penetrate the skull. It’s the only way to stop them.

Part 4

E4

Advance quickly. Stick together. Do not fire unless you absolutely must.

Part 5

E5

Riley does what needs doing.

Part 6

E6

Riley and the remaining USS survivors have one mission: Survive.