Amy Nicholson Rebecca (Margaret Qualley), a mysterious, mercurial careerist, enters Zachary Wigon’s “Sanctuary” with a determined knock on the door of an expensive hotel suite. The room — make that the entire 40-plus story hotel, and the 111 other hotels in the luxe Porterfield chain — belongs to Hal Porterfield (Christopher Abbott), the founder’s son, a self-loathing lump in pleated khakis who is in line to become the successor of a billion dollar company. “Presumptive successor,” Rebecca says. “Successor,” Hal rebuts, with middling conviction. Hal’s ascension to power hinges on Rebecca — at least, so she claims — and his quavering insistence that he can do the job on his own doesn’t convince her (or us) otherwise. Unlike Hal, Rebecca was raised in poverty. (She didn’t even see a dentist until she turned 19.) What clout does she believe she holds? The film has the confidence and generosity to allow the audience to ask its own questions before it makes its first (of many) giddily upending reveals. In essence, screenwriter Micah Bloomberg has ushered the audience into his lair, placed us atop a pile of lush rugs, and now pulls them out from under us one after the other.