Grissom and his team battle the flu when they are called upon by DDA Klein to investigate the deaths of several key witnesses for a grand jury case against a dangerous Las Vegas gang.

Margene's mother visits the Henrickson family; Bill pits Roman and the Greenes against each other.

An astronaut who was missing for 20 years contacts Earth from an alien planet. However, mere minutes have passed for him, and the wormhole that brought him there is unstable. What are the risks of a rescue operation?