The author of the internationally-successful Pony Greenhorse novels (played by the similarly-named Penny Greenhalgh) is in financial difficulty. She’s going to lose the farm unless she can raise some bucks — and quick smart! But she has things in hand. To save herself from insolvency and ruin, she's going to pen another Pony Greenhorse novel — a murder-mystery, set in 1961, on a cruise ship in the French Riviera — but the pulp author is without any idea for the plot.

This is the framing narrative for the show Pony Greenhorse, which plays out like the first draft of a manuscript, as Greenhalgh rushes to narrate and flesh-out the outline of what is sure to be a gripping paperback. The titular Pony Greenhorse is a reformed homicide detective, and famous actor, who is on the run from some dark forces, and attempting to make a new life for herself. Gradually, however, Greenhalgh introduces us to the other passengers and cruise staff, setting up the scene for a murder mystery which, in the fullness of time, leads to a completely logical and satisfying conclusion.

Or, at least, something that will approximate that by the final draft.

Pony Greenhorse could loosely be described as a show about the authorial process, but really it is just a thin justification to show off some dynamic, silly, and highly-entertaining character work. This is not a complaint. It's really quite a fine effort, and there's a vibrancy of sketch work on display here which not only feels of-a-piece within the setting, but also quite refreshing and distinct in the context of the stage. Where Greenhalgh's voice occasionally halters and stammers, her physicality intrudes, at times literally, into the audience. (The Grim Reaper character comes to mind, here, but the hobbled Scottish T-Rex also deserves an honourable mention.)

The show finished on a note of apology; indeed, it felt somewhat unpolished for a show out of preview. Regardless, this was downright fun, and will undoubtedly get better in time. But it's the once-off moments, which Greenhalgh is perfectly-equipped to deliver on, that will really leave an impression.