The mind of a performer, hungry for her big break, is cracked open in Julia Grogan’s one-woman follow-up to her drama Playfight. At first, her dream is in motion: Miss June (played by Grogan) is on a chat show, giving breezy answers about her Oscar nominations and being recognised by monks in Holland & Barrett. And then, with one question from the audience – “Any advice for people who want to be something?” – the stage warps back to reality. Actually, Miss June is a baby ballet teacher, with a class of toddlers ready to be taught turnouts and pliés.

But all her lusting after Daisy Edgar-Jones’s life may have paid off. Miss June has been offered a spot on a TV show, and you can bet she’s told everyone in the town she grew up in – where she still lives – about her good fortune.

Directed by Rachel Lemon, this is a story of success and stardom in reverse which is played out like a horror show. Soon it turns out the producers don’t actually need her, so it’s back to the village hall, jointly used by Twinkly Stars ballet school and an All Addictions group, to beg for her job back and prepare for the end-of-term sharing.

Only a second away from a screaming outburst … Grogan. Photograph: Alex Brenner

Framed as an epic tragedy and told in acts, You’re So Special shows fame as a manic obsession. Miss June has bulging, twitching eyes and is always one second away from a screaming outburst. She speaks to the three-year-olds with a desperate, Dance Mom-esque quality: “You might feel pressure to lose weight – do it,” she commands. When she learns that one child’s parents are TV producers, she sets her sights on grabbing herself some time in the spotlight. And the whole time she is spurred on by the memory of her own dance teacher telling her she was “special” as a child.

Despite being alone on stage, Grogan conjures a vivid whole world. The personalities of the mind-drifting kids are unmistakable through her expert miming, and never once do we doubt her frantic, deep need to reach for higher things. Grogan is a wonderfully watchable actor – you don’t dare look away for fear of missing another flash of a breakdown. She is also painfully funny. Miss June’s career may have stagnated but Grogan is doing brilliant things.

• At Soho theatre, London, until 26 September