At this point, the novel backtracks a couple months to the time of Dmitri's arrest. Ivan, you might remember, was far from the fray in Moscow and only got the message about his father's death four days after it all happened. On his first day back in town, he met with Dmitri, then he went to visit Smerdyakov.
Smerdyakov was laid up in the hospital, very ill after a series of epileptic seizures. Ivan confronted him about a number of things Smerdyakov had said before Ivan left for Moscow. Did Smerdyakov fake a seizure? Why did he want Ivan to go to Chermashnya?
In his usual sly way, Smerdyakov seems to have an explanation for everything, but he still implies that they're somehow complicit in their father's death – or at least that's what Ivan reads into Smerdyakov's promise that he won't tell the police about their conversation.
On his return Ivan had also become madly in love with Katerina, although he denied it to Alyosha.
Two weeks after his return, he confronted Alyosha about whether he thinks he might have wished their father dead. Alyosha reluctantly agrees. After this conversation, Ivan decides to visit Smerdyakov again.