It is a player-made quest event with some fights (safe, won't drop item)
Event time: 15-17/8 (next Mon-Wed) 5:30-6:30pm GMT+8
Event location: w20 Grand Exchange
Register in the first link in top post
Quest complete will receive 100k as reward and complete specify condition will have double amount.
PM "Killer Zoo" or join "Rs At Myorc" friend chat if you have any questions.
p.s. To akira: Welcome to use ancient spells (if you can use it in f2p world).