Don’t expect the slick production values of later years – these early episodes have the usual shortcomings of vintage studio-based TV drama.

But this is an enjoyable wallow in nostalgia that not only takes us back to the genesis of the series but answers the all-important question: What were The Avengers actually avenging?

The grudge dates back to the first episode in which Steed – then a secondary character – pledges to help a police surgeon track down his fiancée’s killers.

As well as surviving episodes from the initial run (including a fragment of episode one), this set includes the entire second series, in which Patrick Macnee finally assumes leading man status, alongside Honor Blackman.