Red crystal

Playing the easier version on veteran difficulty. Race - Necropolis, hero - Kaspar. I think this is the most effective option because the army comes not only from cities but also from necromancy, and you can level 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 this hero, so I had to switch to veteran difficulty.
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.