Three decades since Shizue Takahashi's husband and a dozen others were killed with a nerve agent on Tokyo's subway, she fears Japan could see a repeat of the doomsday cult attack. Another widow, Yuki Niimi, knows the group that carried out the attack only too well. Her husband was a follower of Aum Shinrikyo and was executed in 2018 for his role in the 1995 gas attack.
