V is for ...

... Vortex cocktail

The "vortex" is the swirling tunnel you see in the Doctor Who title sequence.  Also, Captain Jack would travel using a vortex manipulator.

I had a tough time picking a "V" cocktail.  There was an episode Vampires of Venice which led me to look for Venice cocktails.  Then there were the Vashta Nerada from Silence in the Library/Forest of the Dead.  I really wanted to go with this one but had too hard of a time finding a related cocktail -- there was a Tree Shaker, a Forest Funk, a Dave Cocktail, and then a piranha cocktail (the Vashta Nerada were referred to as the piranha of the air) -- but all of those required too much explanation.  And then there was the Vespiform which had a connection to Agatha Christie .. but again a little too much of a stretch, so I settled on the Vortex Cocktail.

Ingredients:

• 1 1/2 oz strawberry vodka
• 1/2 oz coconut-flavored rum
• 1 oz cranberry juice cocktail
• splash lemon-lime soda
• 1/2 lime

Recipe from here.