The plot's about Lucy, who worries from all the noises that there are wolves living in the walls of their home. She interupts her family members to tell them so, but they don't believe her. Her mother is too busy making jam, wonderful jam. Her father is too busy playing the tuba. (Cue Peter and the Wolf - not that that music is used.) Her brother is too busy playing computer games. (More songs should be written about playing arcade-style games.) And then the wolves really do come out of the walls...
Things I particularly loved about it: the rescue of pig puppet! The family considering where to live: the Kalahari? a space station? A tree house would at least be several hundred meters from anything else... I loved the toaster, waiting and waiting to finish toasting while everything else happened around it. The Jam song and jam instrument. The brilliant use of walls and scaffolding.
The surtitles were, however, a constant distraction. I find this with movies too: even if I can understand what's happening perfectly well, if there are words being displaying in front of me, I will compulsively read those too.
The play is on through Saturday at the Hammersmith Lyric, here in London, and will then tour a bit further around the UK, if I remember rightly.