Lord Craighe's short lived assault on the characters was to no avail, they proved much too powerful for him and his zombies and he fell quickly. After decapitating his body and saving the head in a bag of holding (thanks Randall), the party continued on and found a single door marked with sigils of warding, apparently designed to keep something in instead of something out. Using Craighe's head and mage hand, Randall breaks the wards and immediately the strange whiffs of bad smells the characters had been smelling became much more intense. Upon opening the door, the characters saw that the library was filled with a strange golden light, and inside, in the center of the room in a large open space, was a pillar of golden light. The light had a strange, entrancing effect on the characters, causing them to stop and become fascinated, and in some cases causing them to walk forward toward it, entranced by it's seeming structure. It's nature seemed to violate the laws of nature, containing boundless depths of distance inside of it and strange visions of golden towers and domes thousands of times bigger than could have ever fit into the room.
The room itself was a considerably well stocked library with hundreds, perhaps thousands of books. The party decided to try and retrieve the books one at a time for Fimble and hope they found the ones he wanted and contrived a complex plan involving sheets and ropes to try this, but ultimately as they entered the room they found themselves under attack from a large floating eye-like creature with a huge mouth and four tentacles, each of which had its own eye at the tip. Spitting beams of necrotic energy and seemingly able to reflect spells and redirect their energy, the creature attacked, using it's dark magic to turn the party against each other. After a harrowing battle with the creature, they broke its control of the pillar's energy and it became entranced in the same way they had been, eventually falling to the party's attacks right before finally touching it. In a bolt of intuition, the group realized they could seal the rift by returning the creature though it, and pushed the corpse in, causing the pillar, a rift into an outer plane, to seal.
Now free to investigate the library, Fimble selected his prizes, loading up each porter with a selection of tomes and books of all descriptions, and announced that the party was free to claim anything else they wished.
After looting the keep (but leaving part of it unexplored), they rested and then escorted Fimble and his porters back to town, where he paid them and thanked them for their service.