The Turning Tide

This started so well with Dandy and Hugh becoming grandparents and Hugh unbending enough to actually show some fatherly concern for poor Mallory ... and then, I don't even know what to say, was there even a murder? I can't tell. Dandy and Alec have been gently refusing several letters to assist with the strange case of the Cramond Ferrywoman. However, when Mallory decides to invite a group of disadvantaged children to holiday in the grounds of Gilverton they decide they would rather investigate what has occasioned these strange pleas. Dandy and Alec have been approached by the local vicar, Mr Hogg, because their ferrywoman Vesper Kemp has refused to ferry people to and from the tiny tidal island, at first she only refused during good weather but now she has refused entirely and is running around the island barefoot, half-naked, dirty and with her hair in a tangle. Coincidentally Dandy discovers that a friend's young son who died recently actually drowned in the river, but speaking to villagers and the local big-wigs she starts to hear conflicting accounts of his death, leading her to suspect murder. So now there are two mysteries to solve. Maybe it was because I read this book in dribs and drabs but this felt very disjointed and disappointing, I also struggle to believe the truth about the perpetrators - it seems unlikely and I just keep thinking 'but how did they come together?'. Anyway, I have already read the next book in the series (got an ARC which started me on this epic read) so now I'm looking for something similar eg 20th century detective but no knitting or cats. Anyone got any recommendations?