The Haftarah of Chukat is from Judges, the story of Yiftach – but it ends before the really juicy part.
Linear Annotated Translation of the Haftarah of Chukat
The relevance of this Haftarah to the Parsha is the use that Yiftach makes of one of the stories in this Parsha in his argument against the claim of Amon that Israel stole their land.