The Brain Bombs were Strange Devices planted in the brains of the original then un-named Ätlän-tã Fælcons by Lord Milnor, under the command of Fennekin. The party woke up on slabs in Shadowspar Keep, where they realized they had these devices. After finding Thokas, a minion of Milnor, Junpei Iori's bomb was detonated, killing him. He was brought back to life by Geodude, his familiar, for a fee of 10,000 gold. Later, Thom the Dragonborn's bomb began ticking while at dinner with Lord Trant Thumble. He and the others were able to get him to Fennekin's home, where he was saved. Fennekin then asked them to bring him three artifacts before he would remove their brain bombs: The Brazier of Worlds, The Orb of Endless Power, and The Whip of Binding. After some time, they did that, and brought the objects back to Fennekin, who revealed that he was actually a bad guy, and exploded the brain bombs of Aludra the Dwarf and Thom. The last party member, Lord Titus Harper was killed by Ros.
After being brought back to life by Erathis, the party then went on a mission to save the world from Fennekin's Demon Apocalypse. Along the way, they met up with Harper's sister, Adira Harper. As a means of forcing them to help clear out some evil demons, she put brain bombs back into the heads of Aludra and Thom, forcing them to take out the demons. After this, the brain bombs were removed, and the party was able to take down Fennekin for good.