Annie Baker makes her much-anticipated return to Off-Broadway with the world premiere of Infinite Life, a coproduction with Britain’s National Theatre. The play, once titled On the Uses of Pain for Life, was slated for Fall 2021 at Signature Theatre, but it never materialized; Baker’s most recent play, The Antipodes, was produced at Signature in 2017. It takes only a few moments of Infinite Life’s halting and delightfully awkward opening exchange for Baker to captivate with her uncanny blend of the naturalistic and the absurd, honing in on human frailty with a merciless yet empathetic eye, this time trained on patients at an alternative pain clinic in Northern California.