family-tree-Christopher Guest’s sweet TV series “Family Tree” ended its first season Sunday in Los Angeles, where half of the eight episodes were set.

It had followed a character played by Chris O’Dowd on a genealogical trip that took him from England to the U.S. in search of stranger and stranger relatives.

The latest link was to find more about the silent cowboy star Tumbleweed Tim, which led to a visit to his grandson, Bob Balaban, the latest of the Guest stable to get involved in the show. He shows off some spurs, hats, memorabilia and an odd talkie tryout footage. He even takes them to the site of the old studio where the westerns were shot before they are all interrupted by the crisis of the episode: Bea loses her monkey on Venice Beach with Pete.

It turns out well enough that all meet at Al and Kitty’s house. Ed Begley Jr’s Al raises a toast to family and friends amid a group that includes Fred Willard and Guest himself.

But then O’Dowd’s Tom stumbles on Al’s conspiracy room where he figures Dealey Plaza and the moon landing were both chopped up and being held in Area 51. And Neil Diamond’s art has been thwarted.

Accompanying Tom on the entire episode is Ally (Amy Seimetz), who he met a car accident and who he’s been dating cautiously. Things got awkward a couple of times, when he absently picked up a Kama Sutra volume at her book store, or when they both watched a fake HBO costume drama that largely involved a sex scene.

They both swore they’d play it slow especially since it was unclear whether they’d see each other again, before they cut to a scene of passion, a supposedly all night love scene where Tom has even given up his fear (not allergy) of cats.

But it’s time to go back to the UK and they must bid goodbye – it would be a normal place for a short series, or one of Guest’s improv movies to end. The camera, however, lingers on the kiss before they cut to credits, giving rise to a bit of a cliffhanger: Does he stay or does he catch his plane?

Befitting the rest of the charming, low-key run of “Family Tree,” this qualifies as a cliffhanger.