Frog in the whole

Literally a toad in a hole

 'It's because it would be too sickly without it,' explained Dave.

'Yes but it seems so jarring,' said Tuppence.

'That's the whole point,' said Dave, patiently. 'You need the contrast. The flowing melodic bits and then the jarring bits.   The counterpoint if you like.  It's like happiness and sadness, the darkness and the light.  Sweet and sour or whatever.  You can't appreciate the one without the other.  You have to bear in mind, as well, Tuppence, that it was the 1960s and most of these people were out of their minds on a cocktail of drugs. They weren't rational.   That accounts for a lot.  Mind you, being rational isn't everything.  Far from it actually.  When I was in the sweat cottage I...'

Tuppence got up to his feet hurriedly.

'Well I think my tea's probably ready.  I'd better be off Dave, it's toad in the hole, my fave.  Thanks for the chat about Thunderclap Newman's greatest hit.'

Dave stroked his beard thoughtfully, leaned back in his rocking chair and closed his eyes.  'Let the...for argument's sake... toad...as it were...see the...hole?  But why a 'toad'?  Why limit yourself to one amphibian?  Is it in fact, as it were...a frog, or perhaps a newt, even a great crested one?  or another type of amphibian altogether?  But let us say, to prevent us totally busting our brains, 'frog'.  In the 'whole'?  But in the 'whole' what?  Or 'hole'?  But what type of 'hole'?  A black hole, perchance?  And why?  But we never ever do know why, do we.  That's one thing I know for certain. I'll need to give this some serious thought.'