Archibald Christie
Agatha's husband's name is given as Archibald in the Enquirer newspaper, though it fails to go so far as to give the last name Christie. Therefore the page should be renamed Archibald (The Unicorn and the Wasp).
Talk about it here.
Sometime before December 1926, Agatha Christie's husband Archibald began having an affair with another woman who Agatha described as being younger and prettier. This broke her heart but social attitudes at the time demanded her to "carry on".
According to the Enquirer, Agatha went missing following an exchange of words with her husband. She would not be seen again until she surfaced in Harrogate over eleven days later.
Agatha later married again. (TV: The Unicorn and the Wasp)