Humphrey Ker and David Reed clearly relish their roles as Sherlock Holmes and Dr Watson respectively. Hardly a surprise, since they also wrote the script for Sherlock Holmes and The 12 Days of Christmas. Packed with sharp humour, it feels like putty in their hands. Putty, which, at a guess, they will continue to mould as the show runs.

In the best of Christmas traditions, the plot is almost incidental to the piece. Suffice to say, that the song The 12 Days of Christmas gives it a structure from which all sorts of baubles are hung.

There is the mysterious death of a young ballerina. There are the murders of several West End actors, all of them strangely linked to characters in the song. And there is the larger-than-life Mother Goose, whose buffoonery seems to be a cover for many things.

Woven in between like tinsel are the heroes and scoundrels, warts and all. The brilliant observational skills of Holmes are matched by the intelligence of his competitor, consulting detective Athena Faversham (played by Helena Wilson). The brave but vulnerable Dr Watson is countered the bully-boy tactics of Arthur Stone (played by Cameron Johnson).

The delivery is fast, and the humour is racy. Wordplay, send-ups and moments of insight: everything is there. The theatre profession and actors themselves are ripe fruit for satire. So too are topics such as male chauvinism and condescension towards the poor (think Oliver Twist). In a couple of throwaway lines, the importance of men talking about their feelings is aired with shrewd agility. And throughout, a hamming-up of things keeps the tone light and the audience on its toes.

Aside from the main parts, the script allows for other actors to shine. Susan Harrison as Ernie portrays a charismatic youth with a striking voice. Margaret Cabourn-Smith as Mrs Hudson is both funny and astute. Amanda Lindgren uses dance to give a wonderful evocation of the hoops through which actors have to jump to get a part.

Of the songs, The Curtain Falls at the end of Act One and The Dead of Winter are strong, whilst David Reed displays his versatile voice in Houses are not Holmes. Orchestration is dynamic and interesting.

Set and lighting design are striking and effective. Holmes’ sitting room doubles brilliantly as the sitting room of Athena Faversham and the precarious proscenium arch of a Victorian theatre makes its own comment on the action. Lighting effects work wonders in allowing characters to appear from the dark in a rooftop scene with the London skyline behind it.

In the context of all the wit and repartee, the pantomimic elements sit a little uncomfortably, as if those at the helm have remembered that the target audience includes children as well as adults. The histrionics of the final scene, in particular, jar somewhat with the rest, as if trying to overcompensate. There are two types of humour being mined in this show, and sometimes the fit doesn’t feel quite right.

But overall, Sherlock Holmes and The 12 Days of Christmas is a seasonal blend of humour and ridicule, served up with a large spoonful of spice in a mix which adults and older children will enjoy.

The production was directed by Phillip Breen with Becky Hope-Palmer. The designer was Mark Bailey and lighting design was by Anna Watson.

It is a Birmingham Rep production and was originated and developed by Donald Rice and Eva Rice for Heartaches Limited.

Sherlock Holmes and The 12 Days of Christmas is on at the Rep until 18th Jan. For further information visit birmingham-rep.co.uk