The Quickling Tree can be found in any portion of the forested wilderness west of the river. This means that a PC should 's'earch for it in a convenient place, such as next to the Mad Minstrel's clearing. It can be found at any time, but to actually enter it usually requires two corruptions: the extrememly thin and nimble and the very light corruptions. This is because the PC must weigh no more than ten kilos to enter the tree. Hurthlings are often an exception: they can enter the quickling tree with only the thin and nimble corruption (which is required under any circumstances). Also, the weight of the PCs inventory is limited to 160 stones. This means eternium plate mails, crowns of leadership and the like are not going to be useful. In fact it is worth picking up any light armor the PC finds throughout the game and identifying all of it at some point in case any of it is useful in the Quickling Tree.
Quicklings use hand crossbows and dark elven quarrels as missile weapons and drop them as they are killed. Some prior experience with crossbows is therefore useful. Quicklings fall fairly easily in melee, with missile weapons or using magic. They are just very, very fast. Only the king and queen see in darkness and see invisible.
The whole point of entering the Quickling Tree is to eat the corpses of the quicklings as they are killed, which provides speed bonuses. There are plenty of corpses generated for a PC with a good Food Preservation skill, so an amulet of hunger or stomacemptia herbs are useful in the tree. As would be expected, the higher level quickling corpses give better speed bonuses, so the quickling lord corpses should be eaten first. The tree contains a quickling king and quickling queen, whose corpses provide the best speed bonuses if they are generated, but they also shorten the PC's life span. This is where those potions of longevity come in handy for races with relatively short life spans.
Monsters generated in the Quickling Tree are: 75% quickling, 20% quickling lord, 3% quickling king, 2% quickling queen.
The original quickling queen stands on a pair of artifact boots, the Boots of Great Speed, greater identified as follows:
---------------- boots of great speed [+5, +0] (+30 spd)-------------- When worn it modifies DV by +5 and PV by +0. When used in melee combat it grants a +0 bonus to hit and causes 1d3 points of damage. When used as a missile it grants a +0 bonus to hit and causes 1d2 points of damage. It contains the essence of Chaos and Corruption. It modifies your speed by +30. It grants bad luck. Wearing it makes you doomed.If it is desired, the PC may tunnel directly south from the entrance room into the room containing the high level quicklings.
Time passes very quickly in the quickling tree. It is not unusual to enter on day 70 and find that it is day 140 upon emerging. This means the 90 day limit has passed and background corruption will become faster. Ideally a PC will do the Quickling Tree right before the final dive to the lowest levels of the CoC.