The dart finger is another one of Foaly's inventions. It was worn by Commander Root in the first book during his disastrous negotiation session with Artemis Fowl. When worn, it blends in with the actual finger through the use of memory latex. The tranquillizer dart is propelled by a gas valve. To release the dart, the wearer taps the knuckle with their thumb. There have been serious injuries when agents forget they have it on. One of Recon's best Sprites was wearing one and he forgot he had it on. He was picking his nose, and he spent three days on the critical list. Commander Root "accidentally" triggers the dart finger while Foaly and Cudgeon are wrestling. Fortunately, the dart misses Foaly and hits Cudgeon.