It sounded good, at least from a promotional standpoint: A pick-from-alternative endings episode of “Hawaii Five-0,” CBS’ cop reboot.

H50_313_Boss_1c_embed_graphic_heroThe execution, alas, exposed the stunt for exactly what it was — a gimmick, without anything to back up the idea.

The set-up gave viewers the chance to pick from one of three murderers online or via Twitter. The network would then show who was selected in the Eastern and Pacific time zones, with the other two versions available online. (The East and West each came up with different killers, and in terms of plausibility, give the edge to the East.)

Hawaii50Watching both, though, underscored that this was much ado about nothing — a two-minute sequence, shot using different guest actors. Moreover, because the network had to start polling viewers about halfway through the show, there was no logical basis for choosing, no evidence to puzzle over whodunnit; it was just a stunt to see how many people could be driven to participate, and mark if the concept yielded any sort of ratings boost.

Frankly, the alternate endings idea has been around awhile. Indeed, “The Big Bang Theory” producer Chuck Lorre pitched a pilot more than a decade ago called “Nathan’s Choice,” which would have shot two endings (hence the title character’s “choice”), showing one when the episode first aired, and the second when it repeated. The show didn’t get picked up.

Social media has matured quite a bit since then, but if Monday’s episode was any indication, true real-time interactivity of this sort still has a long way to go. And anyone who thinks this represents some kind of breakthrough has clearly been sitting out in the Hawaiian sun too long.

So book all three of ’em, Dan-o. But this empty exercise wasn’t exactly one for the books.