Hanzō could flee underground, but Yanbai's recent strolls around town had not been aimless, either.
Yanbai had originally established Konoha Shinobi Village's water supply and drainage project, and successive Hokage had brought it to fruition step by step.
The sewers were dangerous. The members of the Konoha Military Police Force knew that well.
That was why every manhole cover in Konoha Shinobi Village was locked.
In important districts, Konoha had even worked with the Uzumaki Clan to place seals on the streets. Not just anyone could open a manhole cover or burrow underground.
Unfortunately, Orochimaru's birth parents were civilians, so their home was in a fairly "ordinary" neighborhood.
The manhole covers were locked as a matter of routine, but there certainly were no seals.
Konoha Shinobi Village covered such a vast area that placing seals everywhere would have cost far too much.
Or rather, it was not really a question of money. Everyone in power in Konoha thought Yanbai was paranoid and that defenses this extensive were completely unnecessary.
Konoha changed by the day, with major construction and excavation happening all the time. Putting a seal on every inch of land would have taken too much time, effort, and manpower.
Now Tobirama Senju needed care in his old age and was spending his twilight years quietly in his only student's home.
If Yanbai had not come today, the bedridden Tobirama Senju would have been a lamb to the slaughter before Hanzō.
Two of Konoha's important scientists dying unnatural deaths inside Konoha Shinobi Village would have been a humiliation unprecedented since the village's founding!
Still, judging by Hanzō's circumstances at this point in time, Yanbai did not think he had come to assassinate Orochimaru and Tobirama Senju. He had most likely come to abduct them.
Stealing Konoha's scientists and forcing them