Amid the current crop of summer movies, I can’t think of one that captures the feeling of summer more evocatively than Janet Planet. Much of the story takes place in a rustic house in woodsy Western Massachusetts; by day, sunlight streams in through enormous windows, and at night, chirping crickets flood the soundtrack. The celebrated playwright Annie Baker, here writing and directing her first film, has uncanny powers of observation and a talent for evoking time and place. She also has two memorable lead characters and a sharply funny and moving story to tell.

It’s the summer of 1991. The story begins when 11-year-old Lacy, played by the terrific newcomer Zoe Ziegler, calls her mom from camp and demands to be taken home early; her exact words are “I’m gonna kill myself if you don’t come get me.”

Lacy is a shy misfit with big owlish glasses and a flair for deadpan exaggeration. She and her single mom, Janet, who’s played by a subtly luminous Julianne Nicholson, are extremely close, as we can see when Janet duly comes to fetch Lacy and bring her home. Later at their house, Janet puts Lacy to bed and listens to her vent.

Baker isn’t one to hurry her characters along. Her plays — the best known of which is her Pulitzer-winning 2013 drama, The Flick — have been justly praised for bringing a new kind of naturalism to the stage, especially in the way the actors retain the stammers and silences of normal conversation. She brings that same sensibility to Janet Planet.

Baker includes a few loving nods to her background in theater; at various points, Lacy plays with a small puppet theater, complete with handmade clay figurines, and in a later scene, she and Janet attend an outdoor performance featuring actors in elaborate costumes. But the movie never feels stagey. It was shot on 16-millimeter film by Maria von Hausswolff, who previously filmed the visually stunning Icelandic drama Godland, and her use of natural light and precise, fine-grained details feel transportingly cinematic.

The movie is divided into three loose chapters, each one focused on a friend or significant other of Janet’s who becomes a houseguest for a spell. First up is her boyfriend Wayne, played by a gruff Will Patton, who has a daughter around Lacy’s age but doesn’t take too kindly to Lacy herself. He’s soon out the door.

In the second chapter we meet Regina, played by a wonderful Sophie Okonedo, a free-spirited drifter who comes to stay with Janet and Lacy after leaving a local hippie commune — basically a cult, though everyone is careful not to use that word. Regina initially brings a breath of fresh air into the house, though she proves insensitive and tactless, especially around Janet, and soon overstays her welcome.

The third houseguest — Avi, played by Elias Koteas — is Regina’s ex-partner and the leader of that hippie commune. Avi is the most mysterious presence in the movie, and it’s through his short-lived relationship with Janet that we fully grasp how profoundly unhappy she is.

The title Janet Planet has many meanings — it’s the name of the acupuncture studio that Janet operates out of the house. It’s also a passing reference to the nickname that Van Morrison gave the singer-songwriter Janet Rigsbee, who inspired a lot of his love songs during their five-year marriage. But the title is most meaningful as it frames our understanding of Janet, whose quiet magnetism really does seem to draw other people, especially men, into her orbit. As we see in Nicholson’s heartbreaking performance, it’s been as much a curse as it is a blessing.

One of the movie’s subtlest achievements is the way it clues us into Janet’s perspective, even as it keeps Janet herself at a bit of a distance. Much of the time we’re studying Janet through Lacy’s eyes, and what’s uncanny is the way Baker captures a sense of the girl’s growing disillusionment — that intensely specific moment when a child begins to see even a doting parent in a clear and not always flattering new light. By the end of Janet Planet, not much has happened, and yet something momentous seems to have taken place. You want Baker to return to these characters, to show us how Janet and Lacy continue to change and grow, together and apart, in the years — and the summers — to come.