Vex

Vex is a Imperial thief and a member of the Thieves Guild in Riften and is the Master Lockpick trainer. Vex can usually be found standing in The Ragged Flagon

Personality and relationships
She is affectionately known as "our little Vex" by Delvin and Brynjolf, hinting at a softness for her.

She constantly snaps at other thieves; Qoute, "He said firs not furs, it was a damn logging caravan!"

Loud and Clear
The Dragonborn must break into Goldenglow Estate and raid the safe there, as well as light three bee hives on fire. Speaking to Vex will reveal that she had previously attempted to do the job with Delvin Mallory, but Aringoth, the estate's owner, had stationed eight mercenaries around the land and Vex was wounded in the fight. She will then tell the Dragonborn of a sewer entrance on the northwest part of the island, which will make breaking into the estate much easier.

Side quests
When prompted, she gives four different side quest to the Dragonborn if they are a member of the guild:
 * Burglary jobs
 * Shill jobs
 * Sweep jobs
 * Heist jobs

Vex also offers members of the guild information regarding any unusual stones they may find.

Trivia

 * Vex gives A Warning addressed to Delvin for peeping on her.
 * Vex's Name's meaning may come from similar dragon word Bex, which is used by a Greybeard to open a gate (hence related to opening/picking locks) when the Dragonborn is learning Whirlwind Sprint in the quest The Way of the Voice.
 * Vex's Name may also be a reference to the word Vex, meaning to bring trouble, distress, or agitate.
 * Vex seems to be a romantic intrest to several members of the guild, as dialog from Delvin and Garthar imply that they are attracted to her.
 * Vex carries a large sum of gold (several thousand), but the pickpocketing percentage is 0.

Bugs

 * Vex may accuse the Dragonborn of drawing blood, even if the player has not interacted with a single person in any way. This is known to have occurred during a heist quest.
 * It's possible to remain totally undetected on Heist or Burglary type quests and still fail for being caught, even when no one saw any stage of the crime.
 * Vex may spawn inside the box she leans against in the Ragged Flagon. This can be fixed by exiting and re-entering.

Appearances
Vex
 * The Elder Scrolls V: Skyrim