What news does Mr. Butler bring to Mr. Oates when Mr. Oates returns in Chapter 36?

Mr. Butler arrives at Tobias Oates's house just as he's returned from Brighton to tell him that Jack has gone mad and is holding his maid Mercy hostage so that she won't gossip to the other servants. Tobias convinces Mr. Butler to return home and negotiate with Jack on the premise that he will dedicate his next novel to Mr. Butler.