Various concept in the Callahan's Universe.
“The Law of Conservation of Pain was originally stated in "Laws of Conservation of Pain and Joy...The Law of Conservation of Pain
“The Option at Callahan's Place (and its successors) is the explanation of the peculiar ritual...The Option
“Transit is the term for teleporting living and non-living matter together without the aid of any...Transit
“Translation is the term for time-travel without the aid of any external device. Living and...Translate
“Telepathy is the ability to communicate directly with the mind of others. Patrons of Callahan's...Telepathy