This page explains what’s behind the locked door at the Bend of Time in Chrono Cross: The Radical Dreamers Edition.
If you’ve never visited, the Bend of Time is a small, unnamed island located a short distance west from the Dead Sea Ruins. Inside, there are portals that lead to encounters with enemies from missable locations.
Beyond, there’s a giant blob who wants you to run 3 laps in a clockwise direction near the outer fence. For each successful lap, you should hear a chime sound. After the 3rd lap, you’ll trigger a fight with Flea, Ozzie and Slash from Chrono Trigger.
Boss Battle: Flea, Ozzie and Slash
These goons aren’t particularly strong, but don’t lower your guard. Prior to the fight, equip Red Brooches to protect yourself from Flea’s The Stare. Or your party members are liable to become confused, messing up your strategy.
We suggest focusing on Ozzie, because he can use Max Defense to protect his party from all attacks. When this occurs, there’s little you can do, but keep using standard attacks and missing. Before this happens, build up some Elemental Power, so you can pop off emergency heals.
All three can cast Omega Elements towards the end of their attack patterns. So long as you keep your party’s HP topped up, these shouldn’t hurt too much. However, if the damage is piling up, you could consider casting Diminish to halve damage from Elements. Then whack the fools with standard attacks.
Defeating the trio will earn you three rare gear: the Slasher (or Third Eye), Ozzie Pants and Dreamer’s Sash.
How to Obtain the Dreamer’s Sarong
Once they’re gone, speak to the giant blob again to play a riddle game. The blob will think of a random number from 1 to 20. You can submit your answer(s) by running the corresponding number of laps around the room like earlier, then speaking to the blob. Eg. if you think the answer’s 4, run 4 laps.
You have four guesses–for the first three guesses, the blob will give you a hint whether you’re close enough. For example, if 4 wasn’t the answer, it may tell you to keep going. In which case, run more laps. Get the 4th guess wrong or overshoot and you’ll have to exit the room to try again.
Guess correctly and you’ll receive the Dreamer’s Sarong, which gives you Elemental Power Level 8 at the start of battle. Very nice!
By the way, there isn’t really a strategy for this, since the answer is random. Just keep guessing until you’re correct.