Contagion!
Status
Summary
The castaways find disturbing evidence that Ericka Tiffany Smith attempted to return and rescue them, before being felled by some virus. The decision to return to civilization in her boat vs. staying behind until it is known that they won't infect mankind, divides the group. Throw in an alien who wants to study mankind, disguised as one of them, and the group is in for trouble.