Episode 09 of The Trigan Empire
The Phials of Forgetfulness
aka Vannu’s Poison
The Lokan Invasion (the Collection)
Stad zonder geheugen (Dutch title)
City without memory (Dutch title, translated)
The Phials of Forgetfulness was originally published in 6 installments in issues 274 (15 April 1967) to 279 (20 May 1967) of Look and Learn magazine.