For those of us for whom Stearns long ago won over, Dual is a satisfying ride that – while wandering into generic territory that is relatively new for him – shares his fascination with ritual and themes of individuality, connection and disconnection.

Gillan imbues the two Sarahs with subtle physical differences that are consistently surprising.

It is very clever, interesting, and requires a real deep dive into one's own psychological dynamic.

The premise is so good, and Gillan’s performance is so compelling, that it’s fairly easy to overlook the script’s lack of subtlety and ambiguity.