The Key of A-Kul (also known as Sky Temple Key 10) is the tenth Sky Temple Key required for access to the Sky Temple in Metroid Prime 2: Echoes, but also the only one Samus is not required to obtain. A-Kul, the leader of the Keybearers was the only Luminoth of her squadron to make it to the Sky Temple Gateway, gravely wounded, where she placed her key and left several clues on the Key totems before succumbing to her injuries. The clues help Samus as she can scan and download them into her Logbook to use in recovering the remaining nine Keys.