Monolith
You don't have to see it to believe it.
Overview
Something otherworldly appears on Cary’s daily dog walk in the foothills of the Peak District: a giant stone Monolith, which he’s absolutely certain wasn’t there before. But when he takes his Wife Ellen, Son Dru and daughter-in-law Carmen up to see it, the stone has inexplicably vanished. Curiosity ignited, Cary’s on a quest to prove the stone’s existence - and his own sanity - to his family.
Joe Warner, Tamar Saphra
