Across

1 outlook L(arge)/OO/K(ing) after OUT [‘oo’ = castle on the kingside]

5 seismic MESSI (anag) + 1 + C (many)

9 house Y + OUSE

10 zoophagan ZOO + P<H(otel)>AGAN

11 extra cover EXTRA + C (100) + OVER (6 balls)

12 Eve sEVEnteen (hidden)

14 bioscientist I INSECTS A BIT NOT (minus ANT) (anag)

18 chronologies E(nglish) SCHOOLING OR (anag)

21 Ann (n)ANN(y) [‘nanny’ as verb]

22 revolution REV(erend) + (s)OLUTION

25 bucketful BUCK + (tr)U(mp) in LEFT (anag)

26 Bilbo/bilbo double def [Bilbo Baggins]

27 equinox EQUIN(e)/OX

28 dynasty D(irt)Y/NASTY

Down

1 oxygen (little)E/(tow)N/)sun)G/(t)O/(bab)y/(o)X (anag) [O = oxygen]

2 taunts T(square)/AUNTS

3 operations OPERA + IS NOT (anag)

4 kazoo jacK A ZOOlogist (hidden)

5 showering S(mall)<HOWE>RING [Geoffrey Howe]

6 IMHO IMHOTEP minus PET (rev)

7,19 magnetic fields DEFT MAGIC LINES (anag)

8 concerts C(aught)/ONCE/R(igh)T/S(ocialist)

13 interurban IN/T<ER>URBAN

15 silver fox LIVES FOR (anag) + X

16 Scrabble ARCS(rev)/B(ook)/B(ook)/L(ecturer)/E(uropean)

17 grand cru GRAND + crew (hom)

20 Snoopy S<N(ew)/O/O>PY

23 oiled O(fsted) + LIED (anag)

24 jean/Jean double def