I have the quest to catch a sylesti. I bought a master pet trap and it's in my inventory.
At the battle, I click on inventory. I click on the trap, close inventory; can't click on the sylesti; can't click on end turn.

Return to inventory, click twice on trap so it's white background, try again. nothing

Return to inventory, click on trap, close inventory, try the attack button. I must use capture ability.


Where is the capture ability?

Thanks.

You click on the pet you wish to capture while you are in your inventory section (make sure the trap is highlight green). If done correctly then there will be a net symble when you go back to your battle screen. Do note not all pets are able to be caught.

In the Quest to catch a sylesti the game should provide a trap for you to use, and you can't use any other trap than the one provided for the quest by the game.

In the battle,
> hit 'i'/click the satchel image to go to the battle trap inventory
> Click the net to use (should highlight the trap in yellow)
> click the pet you want to trap of the options above the nets (Should turn the yellow highlight green, and a target symbol () should appear in the top left corner of the sylesti's battle info box)
> then you can close the trap inventory and proceed (you have to have chosen what your sylesti will do (attack/block/skip turn) before you can end the turn, though)

(There are usually three outcomes to capture- Pet is captured, pet is not captured but remains in battle, and pet flees. This doesn't count in the Capture a Sylesti quest/ when using a Master Trap)

The pet was covered by the inventory window, so I couldn't see it to click on until I closed the inventory. I'm not sure what I'm missing here.

But finally I selected "Skip turn" and it said I was victorious. Then it said I finished the quest and I did get the Sylestri.

Thanks both of you.

It was probably that you hadn't selected an action for your sylesti, then- all your pets need to have an action selected before you can end your turn.

When you have the inventory up it should look like this:

Thanks for the screen shot.
My exploration window wasn't sized like that; when I opened the inventory I couldn't see anything. There must be a maximize button, and then it would all have made a lot more sense.