After Caesar's ghost warns Brutus, does he ever interact with Brutus after that?
Act 2, Scene 2 takes place in Brutus's tent in his army's camp near Sardis which is located in what is now western Turkey. Caesar's Ghost enters Brutus's tent late towards the end of this long act and Brutus asks, "Speak to me what thou art." Caesar's Ghost replies: "Thy evil spirit, Brutus." When Brutus asks, "Why com'st thou?" the Ghost replies, "To tell thee thou shalt see me at Philippi." Caesar's Ghost does not actually appear onstage again, but Brutus, just before his death in Act 5, Scene 5, tells Volumnius:
The ghost of Caesar hath appeared to me
Two several times by night - at Sardis once,
And this last night, here in Philippi fields.
I know my hour is come.
So the ghost of Caesar does interact with Brutus a second time as promised at Sardis, although the second encounter is not seen by the audience.