The programme says it has no writers, just a pair of "co-devisors". A chap outside warns: "It's not really a play." Once inside we're standing at metal rails looking down at an empty stage in front of a bare brick wall. For the first five minutes no one speaks but voices and noises pump confusingly from speakers. Ah well, gotta suffer for the Fringe.

But it turns out we don't. Neuropolis is an entertaining and theatrical 55-minute voyage of the mind, from an alley beside Beckett's dustbin to the shores of Scorsese's Shutter Island, sailing from Joyce's Northside.

Gary Duggan and Gavin Logue's play – for that's what it is – follows a young man who has lost everything, including his memory, and who wanders along the streets of Dublin and his own synapses trying to (as another character says) "rein in the old noggin" and figure out what happened to his life. Oh, and his wife too.

En route he encounters clichés of menace and madness, but these are so well written and acted that the stereotypes become a virtue.

The big ideas about pain and remembering are perfectly bite-sized and it all finishes with thrilling energy.