I sat down on the wooden bench. Sweat trickled down my forehead. Lark rolled her eyes at me.

'You have a lot of explaining to do.'

'I know.'

'Then start already!'

'Fine, but are you sure you don't want to eat something first?'

'I already did. Stop procrastinating!'

I sighed, but I still took out some dry sandwiches. I haven't ate anything for seven hours.

'The reason we're sitting here is that sometimes, the more confident that place is safe, the easier it is to break in.'

'...? I don't get you.'

'If someone is certain that they won't be attacked, then they will let down their guard. Take a person going on holiday. Do you think they will be thinking about people attacking them or abducting them?

'I guess not. However, we are talking about the jewel. Even if they have their guard down, it will still be extremely hard to infiltrate. Their defenses are too tight.'

'...Have you ever done battle planning before?'

Lark bit her lip.

'No.'

'That makes sense. Every opponent has a weakness.'

'I'm not dumb enough to NOT know that!'

'Of course. Then it will apply to this circumstance as well.'

'Okay then. So smarty pants, if you're so confident you're right, what is the weakness of the defense of the strength jewel?'

'Well, definitely not barging in head on.'

'...That's kind of obvious. What about above?'

'I'm afraid that the Cogenth members are smart enough to apply an electric force field over the jewel. Some people tried it and they never returned.'

'Ouch. Then what's your plan?'

'Underground.'

'Are you serious?!'

I gave her a glare.

'This plan is perfectly fine. I can not see what makes it so unbelievable.'

Lark looked uncomfortable.

'It's going to take a long time, since it's rock and all. Plus, are you sure it's really going to work?'

I smiled. 'That is where I put a lot of thought into this plan. If you done your homework, you will know that the jewel is blocked by some very, very heavy steel ways. They are liftable, so they can enter the room with the jewel in it. Of course, it is heavy enough that only the lord of Cogenth, Lord Fister, can lift it with a strength booster. There are no doors.'

'This is the most craziest thing I ever heard. Is that the only defence?'

'There is some kind of demon beast that protects the liftable walls.'

'Demon beast..?'

'No ones knows what it is.'

'Oh.'. Lark's face drooped in disappointment.

'So how are we going to get past those obstacles?'

'Didn't I just say? Underground, of course. If we dig to the jewel room, past the wall and the demon beast, we don't have to face the demon beast nor the unliftable walls. Great isn't it?'

'...I guess. How are we going to dig past rock though? It's not as if we can dig a huge hole around here. Also, it's not as if we can dig rock with a mere shovel!'

'I've been doing a lot of research on that. If we use a tunneling potion and an experienced enchanter with us, it will be easy to dig a tunnel to the jewel room in the backyard of the abandoned old house near here.'

I paused to take a large bite out of my dry sandwich. Lark just looked disbelievingly at me.

'It's still going to be tough.' she argued.

'That's not all. This might not be true, but the whole city of Cogenth seems to weaken when it's raining. That includes the rocks and dirt as well.' This was my secret piece of information that could just save my life.

'Cogenth weakens when it rains...?'

'It would seem so.'

She started to panic.

'What's wrong?'

'If that's true, we've only got one chance.' She looked at her watch.

'And we only have twenty minutes left.'