Which detective did Agatha Christie introduce in her novel "The Secret of Chimneys"?

“The Secret of Chimneys,” a detective novel by Agatha Christie (1890 – 1976), was published in the UK in June 1925 and in the US later the same year.

The setting for the mystery story is as follows. A politician requests Lord Caterham to host a house party at his country home, known as Chimneys. The purpose of the request is to bring together the principals in a plot to restore the monarchy in Herzoslovakia (a fictitious European state). Lord Caterham reluctantly complies. However, a murder occurs in the country house, setting off a week of fast-paced events with police among the guests.

The novel introduces the character of Superintendent Battle, one of the guests. Battle is notable for his stolid good sense and careful management of information as a case proceeds. He relies in part on the public notion that police detectives are stupid or unimaginative, when he has a good idea of just what is happening.

Battle is in many respects typical of Christie's police officers, being more careful and intelligent than the police officers of early detective fiction, who had served only as foils for the brilliance of the amateur sleuth.