Life of Pi Part 2, Chapter 57 Summary

How It All Goes Down

In a really, really good turn of events for Pi, RP makes a sound from his nostrils, sort of like a snort. Pi, with his encyclopedic knowledge of animals, knows the sound: prusten.
For tigers, prusten is an expression of "friendliness and harmless intentions" (2.57.5).
Eureka moment for Pi: he can (and must) tame RP.
Pi gets all worked up, blows his whistle, and RP doesn't jump into the water to come shut up the excitable Indian boy.
Pi decides on his new plan: it's time to tame RP.