Just when he thinks he's out, they beam him back in.

How else to describe Leonard Nimoy's enduring, at times conflicted relationship with Star Trek, the franchise that's defined his career for more than four decades — regardless of how many times he swore it off or believed it was finished?

"Countless times, I thought it was done," he admits on the phone from Los Angeles.

But this time, says the 79-year-old actor-director-photographer, there are no more possibilities. Spock, his pointy-eared alter-ego, will live long and prosper. But it will be without Nimoy.