Lelouch was asking his help for saving Nunnaly, and Failzaku just kept asking him about geass and Euphy. Lelouch spilled all the beans, and Ragezaku rages about all the people that have died because of him. But then he rememebers how even he himself knows how you look for penance when you kill people dear to you (he rememebers his father).
So basically he just says Lelouch "Your only choice is to turn lies into truth. You lied about being an hero of justice, so just be an hero of justice from now on to make up for it." and gives him his hand offering help.
Schniezel's guys come in and take him away.
And then Suzaku was a backstabber.