At first, there had only been one lead: come to Blüdhaven and find whoever had sent the text message. But after speaking with the healed Chief, Su Ming discovered two more leads.
That old cripple had not been idle. Recently, he had been helping Young Justice investigate the Shogi Society. The assignment had actually come from Green Arrow, who, along with Black Canary, had previously been attacked by numerous fake Deathstrokes.
Those fakes had done nothing but keep chanting "Checkmate," the Shogi Society's standard line before killing. But no survivors had been left last time. Superboy-Prime had wiped out every enemy surrounding the couple, and afterward, New Checkmate had seemingly sunk beneath the sea.
Green Arrow had not gone into detail, since Deathstroke and the others had been busy dealing with stronger enemies at the time. Still, he clearly had not given up the investigation.
To avoid wasting manpower, he handed the matter over to the kids.
Green Arrow had a grim, burdened persona, and was often even darker than Batwoman. But he had one advantage: he got along very well with children and was happy to bring young people along.
Although his own presence was not particularly strong, and during Barbatos's invasion he had even made a joke of himself by hiding in Gotham's sewers with the Teen Titans for a month, the youngsters still relied on him greatly.
Young Justice had Amethyst Princess, Wonder Girl, Superboy, and Teen Lantern. Their strength was actually quite solid, so the investigation was assigned to them.
The kids were naturally happy to help the adults, but because the team lacked its most crucial detective and strategist—Red Robin Tim—they had found nothing after investigating for quite some time.
So, left with no choice, the children sought help from their neighbors, the Doom Patrol.