In the eleventh blue hardback Hardy Boys novel, Frank and Joe encounter a mystery involving a secret room with a time lock. The mystery is how someone is managing to place death threats within the locked room. To complicate the mystery, the boys keep running afoul of a group of harbor thieves who are stealing high priced articles and evading capture.

Once again, the boys are given their case because their father is out of town and unable to be contacted. They immediately set out to inspect the house where the secret room is and keep running into bad guys on the premises. I think it took them an awfully long time to come to the conclusion that the bad guys were always at the old house because they were using it (it had until recently been totally abandoned) but I suppose the book would have been much shorter if they had figured that out immediately.

The first of two nice surprises in the book was the return of Herb Applegate from the first Hardy Boys Adventure. He has had an expensive collection of jade pieces stolen from him and once again he turns to the Hardy Boys to help him recover it. Herb was a difficult man in his first appearance, but the loss of his jade has nearly broken him and has him begging for the Hardys’ help as if they were guardian angels. The second nice surprise was Hardy chum, Chet Morton, who gets a pretty big role in the novel and acts impressively at a pivotal moment in the story.

The blue hardback has a beautiful cover, but unfortunately, it gives away an important secret of the novel. Overall, this was one of the better Hardy Boys adventures.