As Ivan heads back to his father's house, he feels increasingly troubled. When he arrives, he sees Smerdyakov sitting on a bench outside and is suddenly overwhelmed by his intense loathing for him. But despite this, he finds himself sitting down on the bench to talk with Smerdyakov.
Smerdyakov asks Ivan why he doesn't go to Chermashnya, and Ivan is confused by his question. Smerdyakov then babbles a bit about how concerned he is by the trouble between Dmitri and Fyodor, and how worried he is that Dmitri will kill him for conspiring with Fyodor. He wonders whether he'll get an attack of "falling sickness" (epilepsy) the next day.
Ivan thinks Smerdyakov is being absurd because he isn't supposed to be able to predict when his epileptic fits will come on.
Smerdyakov then worries that he'll be considered Dmitri's accomplice just in case Dmitri does end up killing Fyodor, because he's told Dmitri about the secret signals. If Grushenka arrives to accept Fyodor's money, Smerdyakov and Fyodor have agreed on a special knock to announce her arrival.
Ivan gets even more irritated, but Smerdyakov continues on to tell him that Grigory, Fyodor's faithful servant, is knocked out from the tonic he takes for his back troubles, and his wife Marfa has taken a sip too. If Smerdyakov does have a fit, there will be no one to prevent Dmitri from attacking Fyodor and stealing his money.
Ivan wants to know why Smerdyakov is so convinced that Dmitri will kill Fyodor. Smerdyakov says if Grushenka were to seduce Fyodor, she would convince him to sign over their inheritance to her.
Ivan asks whether that's the real reason Smerdyakov wants Ivan to go to Chermashnya instead of Moscow – Chermashnya is closer just in case Dmitri does commit the murder. Smerdyakov is so irritating at this point that Ivan is about to punch him, but instead he walks away laughing.