In Book 2, Arthur must battle new foes and journey to find answers in order to save a poisoned Sherlock Holmes and others before it's too late. Winter break has ended, and Arthur can’t wait to return to the illustrious Baskerville Hall. With the new term comes an exciting challenge: the Invention Convention, which will grant those with the most extraordinary projects early acceptance into the Circle of their choosing. But before Arthur can stress about which Circle he belongs in, Sherlock is poisoned and all signs seem to point to a foe Arthur had hoped he’d seen the last of…the Green Knight. Arthur will have to befriend new faces and brave encounters with spirits to solve the mystery. And with Pocket and Irene growing busier, and Jimmy sneaking off to unexplained meetings, this new term may not only test Arthur’s wits but his friendships too.