Everyman 3544

[gretta]

Stuck on the last couple
21 a One gets them in Scottish town, right away, mostly (2,3,4)
I think it is in the main, but cannot see why

Also 17d most senseless, two homes being occupied by first letter (7)
I have i-----t
No idea

24a Plan revealed railway track (7) seems to be outings, but I cannot see why
Any help appreciated

[Oldred]

17d in a nest

[gretta]

very funny

[Oldred]

21a i nTHEMai(r)n

[Oldred]

in = home
a = first letter
nest = home

inanest

[Mamyalynne]

24 Outline

[gretta]

leaves me with just one
Plan revealed railway track
o-t-n-e
Think it must be out-n-e
no other ideas

[Mamyalynne]

Revealed - Out
Railway - Line

[gretta]

thanks - mistyped the last word of the down clue