This installment was originally published in Look and Learn issue no. 527 on 19 February 1972.
The Deadly Formula (continued . . .)
This installment was originally published in Look and Learn issue no. 402 on 27 September 1969.
The Fiendish Experiment (continued . . .)
This installment was originally published in Look and Learn issue no. 554 on 26 August 1972.
