The Ambrosia Hotel is a Valley Falls historical landmark and the scene of an unsolved murder from the 1930’s. Local millionaire Harlan McAllister has purchased the hotel and spent the past 6 months restoring it. A week before the Grand Reopening he has invited a series of well-known Valley Falls personalities who all have historical ties to the hotel including famed mystery author Rosemary Clark (last seen in The Dark and Stormy Night). The night’s events are proceeding as planned until one of the guests, Sinclair LeCompt, doesn’t show up for dinner. After checking his room, they find that LeCompt’s door is chained from the inside. Once the chain is cut and access to the room is gained, LeCompt’s body is found. He has been stabbed through the heart. But how is such a thing possible? The only one of the guests with an airtight alibi is Rosemary Clark. After the Will Street Detective Agency is brought in to help with the case, they enlist her assistance with this locked-room mystery. Can you help Rosemary Clark and The Will Street Detective Agency solve the mystery of The Old and Hidden Secret?