The symbol that looks like a big golden book in ‘Book of Oz Lock’N Spin’ online slot, is known as the Scatter Symbol. It's the symbol that has the power to unlock the Free Spins Feature - so keep your eyes peeled! To trigger it into action, simply look to land three or more of them. Just like in other slot games, the more of these symbols you land, the higher number of free spins you can bag yourself. If you land the minimum of three symbols, you'll get ten free spins. However, if you land four, the free spin allocation climbs to twelve. And again, if you can land five Scatter Symbols, you'll receive the full whack of twenty-five free spins. Also, stay on the lookout for a special symbol at the start of the Free Spins Round. Its purpose is to expand to cover the entire reel whenever a win could be potentially completed. Plus, if it doesn't work out for you initially, you can always retrigger the feature later.