You were fascinated by the cube, but before you could examine it, a large blue dragon swooped into the courtyard and released a bolt of electricity. The arc caught almost every one of you, nearly killing Suelfred. You fought back while Suelfred ran for cover behind the cube. But just as the tide was turning, another blue dragon arrived, spitting more lightning. Arkon made a calculated gamble, placing a slow-building creeping cold spell on the new arrival, and it proved decisive. Elros dispatched the first dragon with a massive blow just as the second dragon started feeling the effects of the cold. It fled in a panic; you felt sure it did not survive the spell’s duration.
Looking for a place to rest, you discovered the dragons’ hoard: about 5000 gp in coin plus several magic items: a vengeance ring, a brooch of avoidance, boots of jumping and gauntlets of arrow reflecting. You slept well that night, in a small cavity below a mostly-collapsed tower.
The next morning you examined the cube. It was completely smooth and shiny; a little dirty but unaffected by 700 years of neglect. There was a door-shaped outline on one side, but you couldn’t find any handle or lock. Suelfred used knock to open it. You found a spiral staircase leading down.