2626: Eternal youth

Unclued lights name an authoress (two lights), her hero (two lights), his group (one light, two words), and its members (mostly human).

Across

4    Stimulant gets lad near to collapse at home (9)

10    FBI agents after government department: time to clean up files (10)

14    In mill channel pressure rose suddenly (5)

15    Labourer present: success! (5)

16    Makes up clothes I put on (6)

23    Heinous mistakes, not using outside help (2-5)

24    Close down early, but not entirely (4)

25    Idea spread by first person more than once (4)

29    Lambs he’s butchered here? (8)

32    A lad shortly adopts novel defiant posture, so armed (6)

34    Reported killed in...