13 Little Blue Envelopes by Maureen Johnson

This is a YA book with a great concept, but sometimes a bit too sketchy in the story line.  Even so, it was an enjoyable book and the main characters well rounded and likable.

This is a whirlwind adventure that begins as Ginny, 17, reads a letter from her free-spirited, unpredictable Aunt Peg, who has recently passed away.  The letter contains a plane ticket to London, some money, 4 rules and 13 envelopes that guide her across Europe.

Staying with Peg's contacts or in hostels, Ginny begins to peel away some of the mythic layers surrounding her aunt, even as she falls into thrilling escapades and a blossoming romance.  Throughout her adventures in Rome, Paris, Greece, England, and the Netherlands, the teen collects pieces of Peg's past and learns more about her rapid departure.

The reason Ginny is sent to go somewhere or meet certain people is not always clear; sometimes even she wonders about the point of the exercise.

It's a story to read just for the fun of it.  A good YA book.