Viper 7 - An Eye for an Eye

VIPER 7 - "An Eye For An Eye"
Has the stringent security protocols of one of the most closely guarded British secrets finally been compromised? Is this the end for Viper?
Having recently come back to the UK from their latest operation in Yemen; the Viper Squad has some well-earned down time whilst planning for their next deployment.
In a rare opportunity to celebrate a joint Birthday party for Viper 5, Constance and a ‘welcome on board’ party for the latest member to join the Squad; recently retired SAS Captain, (Milky) Steven Kelly.
On route to the party one of the Vipers is targeted and the unthinkable happens. Violently ‘Taken out’ in a pub car park, then dragged unconscious and bundled into a waiting van by hooded assailants.
Even with all the latest technology at their disposal, their colleague has just totally disappeared.
The hunt is now on and time is ticking.
Who has the knowledge, the resources and the know how to have planned and executed this?