Chrono Trigger/Walkthrough/Chapter 5

Chapter 5: The Trial (1000 A.D. second time)

Guardia Prison

You'll regain control after the trial locked in prison, with your only company a save point and some ethers if you were lucky. You have two choices on how to escape at this point:

Wait out the three days until your execution. It'll take about one minute of real time. Lucca will show up to rescue you and knock all of the guards out. You'll be able to start exploring much farther into the dungeon and all the guards will be knocked out, plus Lucca will be in your party.
Rattle the gate three times, and knock the guard out when he comes to beat you up. You'll have more enemies to fight and can win some mid tonics from the guards.

I'll assume you'll take the long way by breaking out yourself for now. Fight the other guard and use the cup in your cell if you need to restore your health. Head straight to the east and across a bridge to find a single guard guarding a cell. Knock him out from behind and take the chests inside. An Omnicrone will fight you afterwards. Head back to the room with the blue shields, make sure you wait until they turn to one side before attacking. The upper left exit doesn't have much, so try the upper right. Fight the guards on the bridge, and try to sneak past the guards and knock them out for some mid tonics. Knock out the three guards, and open the gate and make sure you free Fritz from the guillotine. Incidentally, if you chose to let Lucca break you out, this is the point where you'll start.

Pick up some treasure in the next room, then head back and go through the left passage. You'll come to another set of four stairways. The bottom left stairway will offer a few treasures, and the top left stairway will allow you to climb outside the castle wall. Climb down until you see an opening, to get into a locked cell you couldn't reach before. Enter the pit at the top left to gain a lode sword. Make sure to equip it. Head all the way back out and go to the top right stairway. You'll be out of the dungeon and back in the grey walls of the castle. Fight a couple guards, then Lucca will show up to knock out a guard if she didn't join you already. Search his body for a bunch of mid tonics, save, then get ready to face a boss, the dragon tank.

You'll need to kill the head first to stop it from constantly healing the wheels and body, then concentrate on the wheels, then body itself. This can be a tough fight at low levels, try to use those mid tonics you picked up and keep your hp above 30. Once the head is gone, try using the fire wheel dual tech on the body for greater damage.

After the boss fight, you'll run over the chancellor, and be chased by Guardia's men to the exit of the castle. Marle will join you and leave her home, and you'll end up trapped in a corner of a forest, where a time gate offers you an unpredictable escape route. You decide to take it and vanish off into the unknown.

Challenging Lavos

Impossible during this stage of the game since you have no access to a time gate.

Continue to Chapter 6: Beyond the Ruins (2300 A.D. first time)