Help needed.

I've just finished a Tony Park novel and am not sure which of these to start next.

Peter May's third in the 'Lewis' trilogy has recently been published and is on offer on-line at the moment. This one is the second and has been on my shelf for a week or two waiting to be read.

Michele Giuttari's book has just been loaned to me by Shadowlight and is the fourth of the former police chief's books I will have read.

But which one to start first?