Listener 4020

[greyfox]

I know some see the Listener as sacrosanct and frown on queries, but I'm not proud (or bothered!). Have managed to complete the grid but have only got about a dozen of the letters of the quote. Can any kind soul provide a hint then I can have a crack at the theme. Also: Is 13ac Airt? If so, why?

[greyfox]

A little perseverance has brought the penny dropping moment and the quote. Would still appreciate clarification of 13 ac. Thanks.

[MartianAlien]

GreyFox "A tiara" is broken(anagram) losing "a" with an extra "a" gives airt . Scots for quarter according to Chambers..

[greyfox]

I spoke too soon. Have got the 11 letters of the protagonists who are in the grid, but fail to see what the other 10 letters to be highlighted.

[Sarrie]

Scottish word for quarter
Lose an A
Anag of a tiara
Lose another letter too.

[Sarrie]

The unsatisfactory bit is not the idea (refer again to the quotation) but how it is put into operation .

[Quizmonster]

Re the protagonists' names, think "star-cross'd".

[greyfox]

Thanks very much for all your help. Are the crossing words 'Castor' and 'comet'? If so that's 22 letters in total?!

[Sarrie]

I letter does double duty

[greyfox]

Silly me. Many thanks sarrie.