Who has done this? A man is dead, and the perp is one of his eclectic mix of extended family. Was it the simpleton and easily-influenced son? The over-ambitious brother? The snooty matriarch? The hired 'entertainer'? Or perhaps the in-laws with 'interesting' foreign connections? Cityscape heads to the preview night of The Last Martini to find out.

As we walk out of the cold night into the warm light of Riccarton House, we are greeted by live piano music and the gentle hubbub of guests mingling, wandering from room to room, and fetching themselves drinks from the special martini menu. Some have chosen to dress in 1920s theme, and it's hard to immediately pick the members of the Martini family from the show's audience – we all freely mingle and grab delightful canapés from trays as they are whisked around the residence by the in-character hospitality team.

Soon, the butler Winston (played by standup comedian Aaron McLoughlin) calls us into the dining room for an announcement. Without giving away too much in the way of spoilers, it's fair to say the evening's announcements don't quite go to plan, as they're interrupted by... a murder! As the audience and the family let out appropriately shocked gasps, we are informed that a certain person has been murdered in the house. It's up to us – the visitors – to listen in on conversations between family members, find clues, and ultimately figure out who did the terrible deed.

There are some masterful touches. The Riccarton House décor is the perfect setting, and the free-flowing form of the performance through four rooms gives a sandbox sort of feel to the murder mystery. Not too sandbox though (Cityscape's delegation would probably paralyze if given too much freedom) – we're cunningly guided in the evening's happenings by Winston's hilariously dry comments and witty instructions.

Having been to a few 'amateur' murder mysteries before, we're delighted to find the professional version takes the whole experience to a new level. The real treat here is the characters created by the actors. Each one is a perfect caricature, and the acting is absolutely on point. It's hard not to snort at the witless interactions of the family's polo-playing son James, and the passionate insults of the interloping sister-in-law Carlotta ("You're like an uncooked spaghetti!"). We become intrigued by the woes in daughter Isabella's love life (or lack-of-love life amirite?) and ride a rollercoaster of emotion for the deceptive, flirtatious and ultimately sorrowful character of the singer, Mona.

So whodunnit? You'll have to go along and find out yourself, but don't wait too long! This mystery is only around until July 10.

The Last Martini
Thu 1 – Sat 10 July
Riccarton House
FB/playspaceproductionsnz
Tickets from Humanitix