The tomb is fairly large and filled with a variety of undead and demon monsters as well several treasure chests. Progress to the north-west to find a large Ornated Stone Door. Aktaios awaits you in that chamber and entering the room will lock the door. Strategies on how to fight him can be found in the article about him. After defeating Aktaios, pick up the Cuneiform Tablet he drops and take it to Imhotep, who will now wait for you near the Gate of Hatshepsut in the Temple of Seti. This will complete the main quest A Telkine in Egypt and start the next one, The Sickle of Kronos.