Welcome To... Chichester 1 : The Spy Of America And The Long Vacation

Set before the events of WTC 2, your plans for a mountaineering holiday are thwarted by your nemesis from a rival organisation - the much feared Grendel Jinx. 
Originally, her plan was just a matter of containment, but everything changes when a long forgotten mission from her past comes back to haunt her.
Seeing an opportunity to keep your organisation at bay (and cause problems), complete her mission, and possibly recruit new personnel she diverts your plane to somewhere more... interesting.