It's A Mysteryby RealTime Gaming

It's a Mystery is a “Who Done It” themed 25 line slot with free spins, a wild, scatters, and a Feature Guarantee. It also has a minor and major local progressive jackpot; either or both of which can be won at the end of any spin regardless of the wager. Of course larger bets increase the chance of triggering one of the random jackpots. The “?” symbol is wild and substitutes for any but scatters. The 'It's A Mystery' symbol is a scatter and 3 or more appearing anywhere trigger free spins.

The Feature Guarantee assures that no more than 150 spins (at any given bet size) will pass before the free spins are activated. After only 1 spin the player can attempt to trigger it with the chances of that happening increasing with each spin.