.... well, not exactly a challenge, but I was piqued by
Mrs John when she wrote about the supposedly easy medallion motif from the Priscilla Book 2.
As I have some free time, and I am looking for medallions to tat anyway, I gave the pattern a try. Here it is all done -

Looking at the original pattern, there are three rounds - the small centre ring, the middle round where the long chains are, and the outer round with the clovers.
And my challenge here was to tat it from beginning to end without any 'tie and cut' in between rounds. And I did!
Rather than starting wirh the centre ring, I began with the long chain. I used two shuttle, wound CTM and slide a paperclip on the thread in between the two shuttle to hold a mock picot and start on the chain.
When I reach the part where the chain joins to the centre motif, I changed shuttle and make the centre ring. To make sure that the picots in the centre ring is long, I leave a short length of thread before starting this centre ring. And the rests of the picots in the ring will take this size. Then I continue with the rest of the chain and the small ring at the top of the chain, and follow the pattern as written.
After I have made seven of the small rings, I made the last chain, joining the length of chain on both sides, i.e to the previous chain and to the first chain. Then, I took out the paperclip at the beginning of the first chain and join the last chain to the mock picot made by the paperclip. The last small ring in this round is made as a split ring.
The last round is followed as written in the pattern.
To Mrs John, give this another try. It is a beautiful motif.