Events before and after a gala ball hosted by Gemma cause a sea change in the sisters' relationships, and challenge her unquestioned dominance over her siblings.
The play opens with the quintet arriving for a photoshoot, and one thing the play does very effectively is set up the five different personalities: Gemma (Charlotte Parry) is the bossy one, her twin Garden (Patricia Potter) the doormat, India (Isabella Calthorpe) well-meaning but ineffectual, Mouse (Alice Sanders) is a dim Paris Hilton type with a string of hipster boyfriends, and Willow (Claire Forlani) is the Meg Griffin.
Richard Kent's set design is a simple affair of sliding white screens, in front of which the sisters' dresses - and the ways they reflect their personalities - provide the splashes of colour. The story turns on the fact that Willow is having financial problems and Garden's husband is cheating on her, but the control freak Gemma jumps in with quick-fix solutions that will make the family's perfect façade stay up, while ultimately improving nothing. Meanwhile Gemma's stoical PA Heather (Ronke Adekoluejo) seems to have more emptahy for the sisters than they have for each other.
"Dan is Gossip Girl? Wait, that doesn't make any sense."
There's a few nicely bitchy lines in Bock's text although Trip Cullman's production doesn't quite bring them to life like it could - Calthorpe in particular makes India so doll-like she's almost blank. And while the play's got its moments, its speedy running time makes it feel a bit unbalanced and unsatisfying: It's basically a soap opera, but one that was abruptly cancelled, and had to squeeze a couple of years' worth of storylines into a handful of episodes.
The Colby Sisters of Pittsburgh, Pennsylvania by Adam Bock is booking until the 26th of July at the Tricycle Theatre.
Running time: 1 hour 25 minutes straight through.