Complex sentence: It is only after Nick calls upon Bud for help in a murder case that Bud realizes Nick is a good person and the two become friends, although he is still somewhat jittery when he and Nick meet.
Split into simpler sentences: It is only after Nick calls upon Bud for help in a murder case that Bud realizes Nick is a good person. The two become friends, although he is still somewhat jittery when he and Nick meet.