I think the first thing to said is this was written in 1939 when people did really look forward to seeing a circus with animals and the understanding of how captivity impacts their lives was less understood than today where it is rare to see such an old-fashioned circus because we are that more enlightened.
This is the second of the three stories centred around Galliano's Circus looking circus life for children where it is Easter and they are all at Westsea although they are due to move on to Liverpool which I'd presume is some way off as it is probably Westsea is either around Somerset or Devon, areas popular for holidays in the UK.
The story is told through the eyes of Jimmy and Lotta circus children where much excitement is caused by the arrival of tigers to join the circus who are kept in a double locked cage.
Jimmy is very much in awe of the tigers and is determined to snuck into them and befriend them from what he sees as their ill treatment while being trained by Fric and his father which he does learning to control them by body language and words.
In some ways this is a high point of the book because in modern english he's being like a 'horse whisperer' gaining their trust and co-operation without the use of whips and shouting at them.
The friendship between Jimmy and Lotta is under threat of being torn about by Fric, the tiger keepers son and helping hand who is spiteful and not averse to telling lies which given it is 1939 would be said to benefit from a smack.
Just as they are able to patch up their friendship, Jimmy's beloved dog, Lucky suddenly goes missing that leads to Lotta going out on a daring mission to rescue him who had been dyed after being sold for five pounds by Fric to a crooked, shady circus man called Mr. Cyrano to use.
As a reward Mr Galliano gets her a black pony that she calls Black Beauty after the Anna Sewell novel no doubt that she learns to ride and perform circus tricks with that are incorporated into their Liverpool show.
Just as everything seems to be going so well Lotta discovers Lal, her mother is ill in hospital in Europe where they've been performing with horses and dogs and The little girl's father, Laddo, may have to go away to another circus because he needs a partner in his act.
As is often the case in Enid Blyton's writing she leaves how this pans out until the next book but we are left pondering just what will happen to Lotta and if she might have to leave this circus and everybody including Jimmy for another.
It's very much a rip-roaring tale that I enjoyed re-reading from my original 1973 Deans hardback edition even if today much of the background to the plot simply would no longer be permitted.