I just saw "Underneath the Lintel" at the London Fringe. I'd rate it at 3/5 stars.
The play is about the adventures of a Dutch librarian as he explores the mysteries unlocked when a 113-year-overdue book is returned through the night deposit box.
The energy of Patrick O'Brien, the actor is amazing. He goes rapid-fire, non-stop for an hour with the show. The props, the slides, the audio are all impeccably organized so that the show flows rapidly from one situation to another with no fumbling and no delays. The energy of O'Brien and the organization for the show were captivating.
The energy and rapidness also detracted from the show. Too many times, O'Brien spoke so rapidly (and slightly muttered) that I couldn't make out what he was saying. That was tolerable, though, because the actions and expressions carried the show through those scenes anyway.
Unfortunately, the show was boring near the end. There was O'Brien on stage, ranting and raving and philosophizing and muttering and trying to make something of a play that had degenerated into superficial philosophizing by playwright Glen Berger about Jesus, the Wandering Jew, immortality, lost loves, etc. My mind wandered and I couldn't wait for it to end.
See it for the energy and production quality. See it for the fun and humour in the first half or so. Those things might make it worthwhile for you.