The Secret Passage by Fergus Hume — Read

Cuthbert was considerably perplexed by the attitude of Juliet's mother. She had always been more than kind to him. On the announcement that he wished to marry her daughter, she had expressed herself well pleased, and during the engagement, which had lasted some six months, she had received him as Juliet's intended husband, with almost ostentatious delight. Now, for some inexplicable reason, she suddenly changed her mind and declined to explain. But rack his brains as he might, Cuthbert could not see how the death of a sister she had quarrelled with, and to whom she had been a stranger for so long, could affect the engagement.

However, there was no doubt in his mind that the refusal of Mrs. Octagon to approve of the marriage lay in the fact that her sister had met with a violent end. Therefore Mallow was determined to see Jennings, and help him to the best of his ability to discover the assassin. When the criminal was brought to justice, either Mrs. Octagon's opposition would be at an end, or the true reason for its existence would be revealed. Meantime, he was sure that she would keep Juliet out of his way, and that in future he would be refused admittance to the "Shrine of the Muses. " This was annoying, but so long as Juliet remained true, Cuthbert thought he could bear the exclusion. His betrothed -- as he still regarded the girl -- could meet him in the Park, at the houses of mutual friends, and in a thousand and one places which a clever woman like her could think of.