I have just watched the movie Life by Daniel Espinosa and my question is simple: How many Calvins were in the movie? I am a little bit confused. When the commander died, there is one out of the station. Then one rises out of the leg of one of the astronauts but as the plot unfolds it seems that theres is just one Calvin. Can you clarify it to me?
There was only one Calvin.
After killing the commander, Calvin got back in to the station through one of the thrusters, IIRC, after they had burned all the fuel it had trying to keep him out.
As for how he got into Hugh's leg, basically, Hugh had some kind of sympathy for the creature and allowed it to go in there, but Calvin was already definitively back inside the station by that time.