Crack the Code

Nikki is looking to expand her friendship circle and try new things. When a day of geocaching turns deadly, she finds herself wrapped up in another murder mystery that brings the grannies and the police together. Their only clue is a series of cryptic cyphers. Can they crack the code and find a killer who intentionally left a trail of clues? And more importantly, can you solve the puzzles before the Nikki, Owen, and the grannies?