Streamers get anxious if they don’t have a show on a wellness island getaway ever-ready. After Nicole Kidman’s best-left-forgotten Hulu show Nine Perfect Strangers (a second season out this week), Netflix’s Sirens leaps into the mix. One of the key pleasures of these series is to watch rich people come undone, though you’re aware that their embedded class critiques are window-dressing. It works when characters are snarky in their delusions. With Sirens, showrunner Molly Smith Metzler plays with expectations, teasing you to anticipate the direction in which the trajectory is headed, until it pulls the rug from underneath. Adapting from her own play Elemeno Pea, Metzler bases Sirens around two sisters sundered by a mysterious high-end socialite, Michaela Kell (Julianne Moore).