Heliodor Sewers

After Hendrick leaves, you'll be in a prison cell. Smash the two pots, then approach the cell door to meet another prisoner who will help you escape.

Once your gear is back, talk to the other prisoner again to find a hidden passage into the sewers.

In the sewers, head right at the first intersection to find a Sparkly Spot containing a Medicinal Herb. A locked door is nearby; you'll need a key to proceed through it later.

Take the other path and follow the linear route until you reach a bridge where soldiers will catch up. If caught, you'll fight them (they are not difficult, but keep an eye on your HP and heal when necessary). Your partner will assist, but you cannot control him.

Continue to the next intersection and take a right. Follow your partner, using crates for cover and timing your movements to sneak past guards.

The final guard requires waiting for him to walk north, dashing to crates on the right, then waiting for him to walk back before proceeding north.

Follow the path to a bridge that collapses, sending you and your pursuers into the caves below.

You'll find a Goddess Statue to save your game.

Head forward into the caves. A Black Dragon will appear; flee from it by dashing towards the screen.

Continue dashing to avoid the dragon and other monsters. The dragon will breathe fire, which you narrowly avoid.

Alerted soldiers will continue their pursuit. A ledge offers the only way forward, leading to a plunge into the water below.