After the death of his father prior to 1868, Howard inherited nearly all of his fortune, being the only male heir. However, a part of this fortune was locked away in a secret bank account, the details of which were to be given to Howard, which had not happened.
Desperate to gain the money, Howard started attending séances held by Thaddeus the Great, hoping to speak to his deceased father and gain the necessary details to access the money. During every séance, Thaddeus divined a partial account number, but never the entirety.
Unbeknownst to Howard, his sister Anne was in possession of the account information, needing only his signature to gain the money for herself. She paid Thaddeus to gain that signature, sending the spiritualist a threatening note when he did not do so quickly enough.
Learning of Thaddeus' swindle from the newspaper, and discovering that her own scheme would soon be outed, she contacted Douglas, who was also present during the séances and had his own scheme going. She relayed the information she had gained, and convinced him to murder Thaddeus so that their schemes would not be outed.
During the investigation performed by Jacob or Evie Frye, Howard was interrogated, and informed of his sister's scheming. Upon learning of Anne's plans, he assured the Assassin that she would be dealt with appropriately.