And with that, he is gone; Shadowfax bearing Gandalf away to Gondor with Pippin, recovering, before him. A perfect opportunity for an inquisitive hobbit to ask questions.
This is the first time since Rivendell where a hobbit has been alone with the Wizard, and Pippin clearly enjoys the privilege, for Gandalf is in the mood to talk.
There is nothing that Sauron cannot turn to evil uses.
The biter bit, the hawk under the eagle's foot, the spider in a steel web!
Saruman, the palantir, and the nature of evil are the main topics at hand, and we hear Gandalf speaking, almost to himself at times, as he processes the causes, impacts and implications of recent events.
Perilous to us all are the devices of an art deeper than we possess ourselves.
The burned hand teaches best.
After that advice about fire goes to the heart.