When they were young their parents (who were from RiverClan and ShadowClan), tested their swimming ability. BeePaw could swim, but RainPaw almost drowned.

Rainpaw- ShadowClan- teased for having a RiverClan name, jealous and resentful of his sister.

Beepaw- RiverClan- excellent swimmer and fisher, loves her mother, but does not remember her dad or brother.