Dude, How'd we get here?

Raio, Decima, Demens, and Zachariel Were caught in a previoulsy unknown adventure, and woke up in the middle of a monsterious humanoid arena, charged with fighting their way out.

DM reward to Aku

Everyone gets 9400 exp, and 10000 gold.

The following can be bought for half price

[5,400 gp] rod of thunderous force [no external clues]
[8,302 gp] +1 valiant dagger [sheds light]
[750 gp] potion/oil of flame arrow (CL 5)
[8,000 gp] ioun stone (scarlet and blue sphere) [no external clues]
[50 gp] potion/oil of remove fear (CL 1)
[300 gp] potion/oil of cure moderate wounds (CL 3)
[700 gp] divine scroll of absorb toxicity (CL 7)
[1,125 gp] arcane scroll of wall of force (CL 9)
[1,125 gp] divine scroll of plane shift (CL 9)
[375 gp] arcane scroll of clairaudience/clairvoyance (CL 5)