“Black Rain” is episode eleven of season one of Helix.
The Ilaria Corporation – which Hatake revealed is controlled by a group of 500 people he says are immortal – having not heard a response from Sutton (not surprising, as, in “Bloodline”, Hatake killed her, removed her head for some unknown reason, then stuck the head in a container in the ice – immortal but not unkillable perhaps) are sending a force to capture the base. Hatake’s answer is to blow it up when they arrive.
Sarah had an injection of Julia’s spinal fluid and is now recovering from her tumour, which seems to be in remission.
The Vectors, under the leadership of Alan’s brother Peter, are not behaving like infected zombies any longer. Instead, they are acting intelligently, with a plan. Whether they would without Peter is unknown.