Am I Missing Something

[alidoc]

Is there a theme to this crossword ? I have answers to some clues that don't seem to have an adequate explanation eg 26a untethers us every second ....gives me nehru which fits but Why?

[bobbinwales]

alternate (every second) letter

[Captain2]

Might help if we knew which crossword?

[Lie-in King]

Some chat here -

https://www.theanswerbank.co.uk/Quizzes-and-Puzzles/Crosswords/Question1850823.html

[bobbinwales]

untethers us every second

[bobbinwales]

was there more to the clue though after the .... as I cant see a definition, 

[Toorak]

There is a theme where the solutions are undefined. If you look at the solutions you have then google them together you should find the theme.

there are also a couple of solutions (or maybe 3?) that are synonyms of the primary definition of the theme.

[Toorak]

Or, I should say, synonyms of a further definition of the theme

[bobbinwales]

ok.... seems there was a collars theme

[alidoc]

Sorry it was The Guardian Crossword 29,189 but for some reason that wasn't published in my post. Thanks for the hints