John Guy is VERY pro-MQOS & doesn't think she did anything wrong until the Babington Plot, which he says she was driven to because of Elizabeth's accord with James I.
However, the book is really interesting anyway, because he takes the Casket Letters apart practically line by line & highlights some inconsistencies in both those & the statements made by the Confederate Lords. Leaves Mary wide open for reasonable doubt in everything but the plot she got her head cut off for.
Interestingly, Guy says the Lords had it in for Bothwell from the days of their rebellion against Mary of Guise's regency, because apparently Cecil was bankrolling the rebels & Bothwell stole the shipment of cash LOL
There were a few fascinating begats as well....apparently after the death of James V, Mary of Guise's 2 most prominent suitors were Patrick Hepburn, Earl of Bothwell (Bothwell's dad) & Matthew Stuart, Earl of Lennox. He states that it was only when Mary of Guise made it pointedly clear to Lennox that she wa having none of him, did he hightail it to England & petition to marry Margaret Douglas instead (thereby begetting Darnley).