In March 2018 , retired Colonel Sergei Skripal ( a former agent for Russia who then provided assistance to Britain and was caught and imprisoned by Russia and later freed in a spy swap ) , and his daughter , Yulia , were treated at Salisbury District Hospital after they were found poisoned by a substance thought to be a Novichok agent
poisoned
Poisoning of Sergei and Yulia Skripal
Salisbury District Hospital