ACROSS
 8. FO I_ ←SARGE← = FOIE GRAS <delicacy>
 9. <stab> LANCE = C_ inside LANE
10. MAD ON NA = MADONNA <pop star>
11. <lizard> MONITOR = NIT inside MOOR
12. <calls> NAMES = ←SE[-a]MAN←
14. V_Y B_E inside NAANS = NAVY BEANS <dried legumes>
16. S_ O_ L_ = SOL <day on Mars
17. ALL outside COHO = ALCOHOL <the sauce>
19. ←EH← X = HEX <magic>
20. "RAZE CANE" = RAISE CAIN <to cause commotion>
22. <dwarf planet> SEDNA = SE DNA
23. M inside TREBLE = TREMBLE <vibrato?>
25. <impressive feats> HEROICS = (HI-SCORE)*
27. <start> ONSET = _O _N _S _E _T
28. S + PENDING = SPENDING <outgoings>

DOWN
 1. B + OLD = BOLD <sort of font>
 2. <figure> LEMNISCATE = _LEMN IS C A _TE_
 3. ANAGRAM* + C_ = ARMAGNAC <spirit>
 4. <novelist> ASIMOV = ←VOMI[-t]S A←
 5. PLAN[-e} = PLAN <blueprint>
 6. <single> UNATTACHED = TAUNT* ACHED
 8. <well-groomed men> METROSEXUALS = (EXTOL MASSEUR)*
10. (.e)MINIST RATION(a.) = MINISTRATION <provision of aid>
13. (MUST RELIVE)* = MULTIVERSE <different versions of reality>
15. <rail> BALUSTRADE = BUS TRADE outside A L
18. HM inside HENCE N = HENCHMEN <minions>
21. <hostile> AVERSE = AVERS _E