Before he could train with Eorlund Gray-Mane, he made a promise to Gerdur in Riverwood to request aid for it from the Jarl.

(Yes, he did in fact go through the Vanilla start)

When he got there, after completing his duty he was given yet another request: Retrieve an item called the Dragonstone from Bleak Falls Barrow near Riverwood. The Barrow was an ancient Nordic burial site. Hverg would hope he wouldn't run into resistance, but an old War-Smith knows how to predict danger, so he decided to grab someone nearby for backup.