I found that the episode 'As Time Goes By' how much the Library meant to Sam. All that knowledge. Another option to bring his lover back.
Sam was breathless, gazing upon the library shelves. He'd opened the door with the key from Henry. The one that his grandfather had given his life for; to stop Abbadon. Sam's hands shook and he rubbed them together, feeling that they were cold. This room was filled with the knowledge of thousands of years. Every spell, incantation, object, and book... The shelves reached the ceiling and he stepped forward, his steps echoing in the enormity of it all. He swallowed, resisting to dive into the first aged book he found. The smell of paper and slight paper must were intoxicating. There had to be some sort of preservation spell over them or they would not be in such good condition. He could see the room was round and symbols he'd never seen before were carved into the ceiling.
Sam took deep breathes and reached the center, where it spider-webbed out; clearly labeled with each category. Witches, Goblins, Ghouls, Spirits, Demons, Vampires, Werewolves, Monsters... Sam's eyes rested on the sign that was in old, swirly text. Angels. And then he looked to one that was in thicker, darker letters. Deities. Sam looked between them and turned down the one for angels. He browsed the shelves. They were some what dusty, but the lettering was clear, even refurbished. There must have been a time when a librarian took precious time to care for these items. They were organized beautifully. Sam wished he had the space to store his items like this.
'Cherubs' was the label for a large shelf, with books, scrolls and a few arrows. Sam noted that the scrolls were neatly in racks and the items were behind glass, but not locked. This library only needed one key after all. He looked to the next section and the next. Angel soldiers. Angel watchers. Guardian angels.
Sam took a deep breath. Archangels. And there were their names! Micheal, Raphael, Lucifer... Gabriel. Sam's hand was shaking was he held out a hand at the nearly bare shelf. The archangels only had two or 3 items each. Gabriel only had a book, a scroll, and one page about Gabriel's horn of truth; but there was no brass trumpet. He took the items, tucked them securely under his arm and walked back to the center of the room, where there was a large polished wood table and at least two dozen wooden chairs. He set down the scroll and opened the leather bound covers. He ran his fingers down the age softened pages and closed his eyes, making a quiet promise.
"If there's a way to bring you back, it'll be in this room." He murmured and sat in a chair, moving himself close to the table to read. The light was perfectly made to shine on the table. He'd read every word. Every scroll. He'd look in the Angel section some more if there was nothing here, but he'd keep this book and scroll for himself. He'd look for an angel purgatory or hell next. And if not, he'd tear apart the Deities section on Loki, the Trickster. He wouldn't stop until he found a way to bring him back.