General Method Description

Jennica's ring is a reward for the completion of the quest Spirit of Summer; when activated near an appropriate Wilderness portal, it transports the wearer to a part of the Spirit Realm. One of these portals is located in the Forgotten Cemetery and has an interesting little feature. The Spirit Realm is like a mystical "inverse" of RuneScape, so there are several game features programmed so that what happens in one world causes the reverse effect in the other. The cemetery contains four coffins; if you close the coffins in the "real world", they open in the Spirit Realm; if you then go to the Spirit Realm and close the coffins there, they open in RuneScape, and four level 79 ghosts are created. These ghosts are quite easy to kill and have very good drops, including lots of runes, mithril arrows, noted limpwurt roots, and even prayer potions -- they are one of very few low level monsters to do so. They also drop ranarr seeds -- the only type of seed they drop. The quality of the drops means that you can make good money fighting these, though the profit per hour is somewhat restricted by all the time spent closing coffins and moving between realms.

Note that while the ghosts themselves are not difficult, you will be in fairly deep Wilderness (level 30) most of the time, so revenant attacks are always a possibility. My assessments assume the occasional need to fight off or run from a revenant (which isn't hard to do anyway if you are near a Spirit Realm portal.)

The most convenient way of getting to the Forgotten Cemetery is using the lava maze teleport of a lava titan familiar.