Lost Her Marbles

Lost Her Marbles is the second caper of the Thieves' guild which is only completable after the quest (Buyers and Cellars) and the first caper (From Tiny Acorns) are complete. The second caper requires you to pickpocket various NPCs for Flame fragments, pieces of solidified fire that they found after a magician had a serious mishap and blew herself up. 32 fragments need to be gather and they are scattered in various places, no more than 6 in one place.

Walkthrough
After speaking to Darren and Robin, it's time to go fragment hunting! To hunt them, just simply pickpocket the target. Successful pickpocketing attempts do not always gain fragments; the standard loot may be gained instead. Several attempts may be necessary to get one fragment. The same NPC can be pickpocketed repeatedly until all 6 fragments in the area are gained. A message in the chat box appears when the player gets a fragment. (The player is not told, however, if and when they have gain all the fragments in an area.) It is a simple process to right click any of the fragments you have obtained (or by talking to Robin in the guild) and choosing check, to see which of the NPC's are still available to be stolen from to obtain fragments. Once all 32 fragments are obtained, none more can be gotten from any NPC. Return the fragments to Darren, every 8 you return you will be prompted to claim a random reward from Robin.
 * The farmer or farmers around Lumbridge.
 * The Master Farmer in Draynor.
 * Men and women around Lumbridge.
 * H.A.M. members in the H.A.M. hideout.
 * Guards anywhere in Runescape (although Robin only mentions in guards in Lumbridge and Al Kharid. Al Kharid warriors can be pickpocketed for fragments even though they are not technically 'guards'.
 * Rogues in the Rogues' Castle in the high Wilderness.
 * warrior women (it only says warriors. other kinds of warriors may work aswell)

Reward

 * 49 Coal.
 * 136 Teak logs.
 * 37 Raw lobsters.
 * 46 Gold ore.
 * 19 Raw swordfish.
 * 43 Nature runes.
 * 255 maple logs

all of these (exept the nature runes) are noted. Repeat obtaining these rewards until you have completed the caper. Congratulations!

When this caper is complete, you recieve 5000 theiving experience. A general store selling useful theiving items opens, the guild expands further and wall safes can be cracked.