The Denver Post calls this an "addictive combination" of pureed cucumbers, basil, and vodka (or soda water for nonalcoholic version).

Cucumber Cool Martini
Ingredients
1 1/2 ounce cucumber simple syrup (recipe follows)
1/2 ounce fresh-squeezed lemon juice
4 ounces vodka
4 basil leaves
Peeled cucumber slice for garnish
Kosher salt
Directions
In a martini shaker, add a few ice cubes, the basil, the lemon juice and the cucumber syrup. With a wooden pestle, muddle the basil with other ingredients. Fill the shaker with more ice cubes, add the vodka and shake well. Strain the liquid into a chilled martini glass; garnish with a slice of cucumber dusted in salt.
Cucumber syrup: Peel 1 large cucumber. Cut off the ends, cut into chunks and blend in a blender. Pass through a cheesecloth and chill. Discard liquid. In a small pot, whisk together 1/2 cup sugar and 1/4 cup water. Bring to a boil and chill. Add 1 part of syrup to 2 parts cucumber puree and chill until ready to use. Makes about 2 cups.
Nonalcoholic Cucumber Soda
Mix 1 1/2 ounces heavy syrup with 6 ounces soda water. Serve over ice.
The vodka in the Cool Cucumber Martini is not the focus of the drink - it instead acts as a flavor intensifier, as often experienced in savory cooking.