Complex sentence: Not long afterwards, Monkhouse Lee issues a warning to Smith against Bellingham, explaining he has called off his sister's engagement to Bellingham, after Bellingham confided in him a terrible secret of which he has sworn to keep silent.
Split into simpler sentences: Not long afterwards, Monkhouse Lee issues a warning to Smith against Bellingham. He explains that he has called off his sister's engagement to Bellingham, after Bellingham confided in him a terrible secret of which he has sworn to keep silent.