Jump down on him and plunge a dagger through his neck.

Without making a sound, you pull out your dagger, and drop down from your perch. The wind whipped past your face and you land on the unfortunate trader. His face hit the dirt and you use the last of your momentum from the drop to thrust your blade completely through the back of his neck and out the front. The man gasped what little air his last breathe could muster and went quiet. You pull the dagger out of him and watched the his life blood spill out of his two new orifices. Those damned humans don't deserve much else.

You use the man's robes to wipe the blood clean from your metal and cut the ass free of its burden. The animal might not live long on its own, but you'd be damned if you were the one to kill a helpless animal. With any luck, it'll become the meal of one of the several forest predators.

You plunder the wares of the late trader and walk away with food, wine, several bits of jewelry, and marijuana found in a secret compartment. Nothing too heavy or useless to lug around. A rogue does need to remain agile in hostile territory. You turnover the cart as your final "fuck you" to human commerce and search the trader for anything on his person.

Besides his clothes, he carried a knife that failed to protect him in his final moments, plenty of Laarse coin that is useless in the hands of an elf, and a letter sealed with a royal stamp.

Not only was this man peddling his goods but he functioned as a messenger for the royals. It's a shame he wanted to save a couple coin by avoiding the tolls.

You leave the trail and climb a nearby tree before opening the letter. You didn't want to be caught off guard next to your kill while reading from royal parchment. The humans would need to come up with a new form of **** if they found you like that.

Dearest John,
I can not stop thinking about you every day since you left for battle. Father has informed me that you'll return to the castle after two years for a short break before returning to the front. Every man and woman needs to preform his duty during these trying times, but I can not wait that long. I have arranged for myself to leave the castle and covertly travel to the Black Horse Inn. It should be no more than three miles from where you are. Father is not in favor of his daughter leaving the castle with only one man escorting me, but it is all that we can spare without drawing attention to myself. Please. Meet me on the fifth of April. I need to see you again.
Your love,
Princess Tori

You smile and laugh at the letter. The princess is travelling with a single escort and her lover will never receive the message. What's more is that if you kill or even capture the princess, you'll be hailed as a hero back home.

You mark the important details in your notes and stuff the letter into a knothole. Your coded elvish writing will keep the princess safer than her personalized letter would have.

Now to find the Black Horse Inn.