The Secret Key is a Key Item in the Sinnoh region games which allows the player to access a special room in Galactic Eterna Building which leads him/her to the Rotom Room. This item was introduced during Generation IV and with the key it gives the player access to five devices which can change Rotom's form at will. It is one of four Sinnoh based event items, alongside the Member Card, the Azure Flute and Oak's Letter.