This remains one of life’s most important lessons, applicable in all manner of circumstances: If something looks and/or sounds too good to be true ...

it almost certainly is. Be wary. Director Zoë Kravitz and co-writer E.

T. Feigenbaum have concocted an intriguing little thriller around this premise, but — alas — the result would have played better as a one-hour episode of television’s “Black Mirror.” At 102 minutes, Kravitz’s film wears out its welcome, mostly due to a protracted first act that is much too long.

Apartment mates and BFFs Frida (Naomi Ackie) and Jess (Alia Shawkat) work together as cocktail waitresses for a catering company that’s often hired by upper-echelon clients. Frida has long been intrigued by tech billionaire Slater King (Channing Tatum), who recently reappeared after having dropped out of sight for a year, following bad behavior and a series of scandalous headlines. He has been making the media rounds on an apology tour, and the public seems willing to forgive and forget.

Among other things, everybody is fascinated by the fact that he has bought his own private island, where all food is grown and raised in a self-sustaining manner. A bit later, Frida and Jess crash a posh event featuring King; an accident involving high heels brings him to Frida’s rescue. They spend the evening revolving in and out of each other’s orbit, but then King begs off, explaining that he and his friends are heading to his island for a retreat.

She watches.