Biggles's attitude at the start of Hatchet is so fun to contemplate. This is the bit that strikes me particularly:

Again Biggles studied the face of the visitor. 'Were you very fond of your uncle?'
'Yes. He was always kind to me and my mother. I admired him, too, because I knew he was a brave soldier.'
'Tell me this, frankly,' requested Biggles, curiously. 'Had you any other motive in coming to see me, apart from warning me of my danger?'
The boy hesitated.
'Speak up. You're safe here.'
'I thought you might be able to help him.'

Biggles is absolutely leading Fritz to that request, he wants Fritz to ask him for help - but then once Fritz actually spits it out in response to Biggles's prompting, Biggles seems to realise what he's doing and backtracks wildly, and then it takes him several weeks to build back up to that point again.

But words cannot express my love of his conversation with Raymond, in which Raymond basically says, EvS might have information vital to national security and that could prevent thermonuclear war, find him and offer to rescue him in exchange for that vital information - and Biggles refuses! He's ok with the finding and rescuing bit, but he'll only do it for free <333