There is so much humor, much of it understated. I'll give an example. Sennia is determined to go to Egypt, all the adults are afraid to tell her no. It is left to Amelia to do so, and she feels she has convinced Sennia she must remain in England. Horus shared the cabin of Basima and Sennia.
Nothing further is needed to get the picture.
I think it is a shame there are no action figures of mystery characters. This series is continuing in the excellent tradition started years ago.