This week the new improv sketch comedy Thank God You're Here will air two episodes with Star Trek angles.

Monday night, April 16, the guest stars on the show include Jason Alexander ("Kurros" in "Think Tank") who, according to the promos, will take part in a Trek-ish skit aboard a pseudo-Enterprise bridge set. Monday night's one-hour episode airs at 9 p.m. ET/PT, 8:00 Central, on NBC after Deal or No Deal.

Wednesday night, April 18, George Takei will be the principal guest star. That will air an hour earlier at 8 p.m. ET/PT, 7:00 Central — again on NBC for a full hour.

"It was a terrifying experience," Takei told the crowd of fans at the Grand Slam convention this past weekend. He explained the premise of the show: "They invite about four actors to each one of the shows, but we know nothing about nothing. No scripts, no rehearsal, no nothing. We show up, and there's a curtained-off area, and we're escorted back there, and then they ask us to take our clothes off and put [a costume] on, and so we put on whatever they give us, and then they take us out of that curtained-off area, we go on stage, and there's six or seven hundred people in the audience all, you know, eagerly waiting for you to do something.

"And then they push you through a door, and there's a group of improvisationalists, and they look to you and say, 'Thank God you're here.' And you gotta go into the bit and start improvising. I mean, it's a struggle for survival with these comics!

"So do tune in next Wednesday, April the 18th, to see how I survived on that terrifying show!"

George told us backstage that for one of his skits, he was dressed in a hospital gown. He thought he would be a patient, but it turned he was a doctor and had to operate on a patient. That was a particular challenge because, "We're desperately trying to be funny, and it's a situation of life and death!"

In another skit, he was dressed up as a common working guy in a windbreaker. He stepped into a governmental office, and was confronted by a bureaucrat asking him to explain his unemployment claims. When the bureaucrat would frown, one of George's improvised lines was, "Oh, there's that Condaleezza frown!" (referring to Secretary of State Condoleezza Rice).

(Robert O'Reilly, "Gowron," was in the Green Room with us, and he said his response would have been, "Of course I've been collecting unemployment for 40 years, I'm an actor!")

Thank God You're Here is hosted by David Alan Grier, with Dave Foley serving as the "judge" who determines which guest star wins a trophy at show's end. It premiered last Monday.

Remember, that's Monday at 9:00, Wednesday at 8:00 — check your local listings, or just program your TiVo.