Bellerophontes didn’t know that his own death was requested in the letter he brought. Proteus asked his in-laws to get rid of the messenger. Instead of killing him on spot, the king asked Bellerophontes to kill the Chimera, knowing that he would never come back alive.
Bellerophontes was excited and went for advice to Polyidus or Polyeidos, the wisest man in Lycia. Polyeidos told him he would need the winged horse Pegasus.