Red crystal

I'm playing the easy version on Veteran difficulty. Faction - Necropolis, hero - Kaspar. I think this is the most effective option because the army comes not only from cities but also from necromancy, and by leveling up other units through mentoring. Battles in the city, due to raising and replenishing mana, proceed with almost no losses. The initial period of hero leveling was difficult. It didn't work out on the hero, so I had to switch to Veteran.
But a problem arose. I can't find the shipyard workers. I've searched everywhere. Either I don't understand something, or I killed someone before getting the quest. Please advise.