BtVS Season 5

I'm looking for a fic Where spike and Buffy go on a mission in a castle alone then the scooby come. Some monster living in the donjon and the cook is a bad guy. I remember that riley still there and catch Buffy and spike together in the tub.

Could it be Charms of the Clarion by Eurydice ? It's on her site too.

When the Council approaches Buffy with an offer she can't refuse, she finds herself in another world, with Spike as her necessary partner. Set early Season 5. - Complete

It has the castle, the cook and the monsters. And the tub.

That's the one! Thank you it's been years since i want to read it again.