It is the first meeting of Frederic and Catherine, who will become lovers in this story. They are standing some distance apart and facing in opposite directions. Two cameras move across the stage towards them, operated by other actors. Giant close-ups, projected between the couple, make it seem that they are gazing into one another’s eyes (video and projections by Simon Wainwright). Film and theatre fuse. In playing off one another, they movingly convey the essential solitariness of the characters, even as they reach out to intimacy.

Pete Brooks and Andrew Quick have co-adapted (and also co-direct) Ernest Hemingway’s semi-autobiographical novel about American Frederic’s experiences in the Italian ambulance corps during the first world war. At its best, their production offers a vivid physical equivalent to Hemingway’s stark prose style: detailed descriptions paint pictures of surface realities while hinting at hidden emotional stresses.

The first half effectively darts between love story and war action – images of maps, forests, words from the text, trains, soldiers etc flow, flash and stutter about the stage. The second half, however, focuses on the lovers’ stay in Switzerland – arguably the least interesting and certainly the least dramatic section of the novel. Technical effects become decorative, momentum falters and the actors seem unsure whether to perform to cameras or to auditorium. Even when only partially successful, though, Imitating the Dog is still, to me, one of the UK’s most interesting companies.

• A Farewell to Arms is at the Dukes theatre, Lancaster until 25 October, then tours