In the second book in the Sam & Friends Mystery graphic novel series, canine sleuth Sam is bored at the prospect of spending a cottage weekend at Sagawa Lake - until she hears that the lake has a deep, dark secret. This is exactly what Sam wants to hear and sure enough, with help from Jennie and Beth, Sam finds an old diary hidden in the wall of their cabin and what they read there is chilling. Is it the key to the secret of Sagawa Lake? What about the strange face painted on the rock, near the water's edge - and the creepy cave nearby? Something lurks in the depths of the lake. All they need is proof, which Sam is determined to obtain at all costs. As always, the mystery-solving trio of Sam, Jennie and Beth blow up events to scary proportions and young graphic novel readers will furiously turn pages to reach the climax - and a surprising solution to the mystery.