Another fun one; I somewhat prefer the inquisitors with slightly more obscure vocabulary and slightly less messing with clues – perhaps because at least I stand a chance.

In the completed grid, one member of a family is leaving a location. One member of another family is entering the same location. Each uses the same technique to pass an obstacle, different in each case. Solvers must highlight both members. Unchecked letters of the unclued families, location, technique and obstacles could form LOCAL ACT, VIVA RACE.

  • 8ac: URAO: Beginning of unholy row over onshore deposit: U(nholy) + OAR (row) reversed
  • 9ac: GATS: Guns to follow in retreat: STAG (follow) reversed
  • 12ac: TENNOS: Recall verse titles: SONNET reversed
  • 13ac: SOREE: Rail about joining members of secret service: RE (about) inside SOE (ref. Special Operations Executive)
  • 15ac: DROMOI: Gypsy involved in swindle; the first to occur in Irish racecourses: ROM (Gypsy) in DO (swindle) + I(rish)
  • 18ac: MOA: Bird no longer starts to moult outside aviary: M(oult) O(utside) A(viary); ref. Moa
  • 21ac: RENAME: Marlene left out mobile to call again: *(MARLENE) - L
  • 26ac: FOEHN: Wind flipping over fluttering hen: F(lipping) O(ver) + *(HEN)
  • 27ac: AROUSE: Nothing in a trick generates alarm: O in A RUSE
  • 29ac: OGEE: Moulding's highest point apparently missing: APOGEE - AP(parently)
  • 30ac: DRIP: Weak person finally shed tear: (she)D + RIP (tear)
  • 1dn: AUTO: Mini drama?: Double definition
  • 2dn: RANEES: Princesses fled uprising to await further: RAN (fled) + SEE (await further) reversed
  • 3dn: ION: Play by Euripides – one currently being performed: I (one) + ON (currently being performed); ref. Ion
  • 4dn: EASE: Manoeuvre bit by bit to stop Corps leaving: CEASE (stop) - C(orps)
  • 5dn: ISOPOD: Woodlouse say, in case belonging to audio player: SO (in case) inside IPOD (audio player)
  • 6dn: DARI: Organized raid to find grass: *(RAID)
  • 7dn: ELEGIES: Support that is shown in El Salvador for songs: LEG (support) + IE (that is) in E(l) S(alvador)
  • 9dn: GOLEM: Robot to work with moon vehicle: GO (work) + LEM (Lunar Excursion Module)
  • 10dn: TSAR: Despot so far heading north in Turkey: AS (so far) reversed + TR (Turkey)
  • 11dn: VENOM: Divers move to contain nuclear poison...: *(MOVE) around N(uclear)
  • 14dn: CARAFES: ...carriage made safe in flasks: CAR (carriage) + *(SAFE)
  • 15dn: DOE: Drover regularly encountered deer: DrOvEr
  • 17dn: FATHOM: Discover money in short: FAT (money) + HOM(e) (in, shortened)
  • 19dn: AFORE: Going about Faroes almost getting lost once: *(FAROE(s))
  • 20dn: PLEURA: Dispute besieging ancient city's side-walls: PLEA (dispute) around UR (ancient city)
  • 22dn: MING: Aircraft designers engulf navy in stink: MIG (aircraft designers) around N(avy)
  • 23ac: CELL: Mobile phone's a disappointment by the sound of it: homophone with SELL (disappointment)
  • 24ac: CAEN: John goes round Eastern French city: CAN (John) around E(astern)
  • 25ac: NEPS: Dispensaries stocking up catmints in some places: diSPENsaries reversed
  • 28ac: ODD: Out-of-the-way force deserted: OD (force) + D(eserted)

It then turns out that a LEMMING, a member of the CRICETIDAE family, deals with a CLEVE by OVERLEAPING it, while a SALMON, a member of the SALMONIDAIE family, also passes FALLS by OVERLEAPING. (LEMMING appears vertically downwards through CLEVE, while SALMON goes upwards through FALLS. Nice touch.)