The principal theatrical event of the week is the production of a five-act historical drama by Mr. W. G. Wills, entitled "Mary Queen of Scots." The subject has been often dramatised, and recently we had a dramatic poem by Mr. Swinburne on the subject of Chastelard's devotion to his mistress and his unfortunate death, which had high merits. This unhappy amour is also the theme of Mr. Wills's tragedy, but he has treated it in a different manner. There is much poetic dialogue in Mr. Wills's drama, which would undoubtedly have gone well with the audience had the performers permitted it to be heard, or the unquiet state of the house (it being a benefit night) not rendered it impossible; as the case stood, we were compelled to take nearly the whole of the first act for granted. It treated of the happy days of Marie Stuart, when at Fontainebleau she was free to enjoy all the pleasures of the palace and the garden - pleasures among which Chastelard's passion was likely to be of rapid growth. The poor fellow, however, is sentenced and banished; and shortly afterwards Marie takes an affectionate farewell to France, when she is followed by her faithful retainer into Scotland. In the second act we have Marie's disputes with her Protestant subjects, and honest John Knox comes into prominence; but the Queen (Mrs. Rousby) proves equal to the occasion, and the recalcitrant pastor is compelled to surrender. The part is assumed by Mr. Rousby, and is supported by him with all or more than his usual force, but does not yet set [sic] easily upon him. As the play proceeds the character becomes more important. The author has not chosen for it a rigid outline - which might have better suited it for stage-playing - but has ascribed to it a passionate disposition which carries Knox through several mental moods, and at length causes him to be tempted by Marie's beauty and suavity. At the end of the fourth act we find him struggling with his feelings, which he delineates in rather tooo long a soliloquy, but which to the dramatic poet is nevertheless highly creditable. The fifth act shows the fatal culmination of Chastelard's love, and the execution of the infatuated youth. The piece is placed on the boards in the most costly style; and the scenery, which is magnificent, does honour to Mr. F. Fenton and Mr. Emden. We have omitted to state that the part orf Chatelard was committed to Mr. Charles Harcourt, and furnished him with opportunities of which he was ambitious to take advantage, but not always with success. Mr. Harcourt yet stands in need of much discipline and more practice, before he can claim to be a complete actor. The residue of the parts was respectably cast, so that the entire action was smoothly performed; and on the whole, the play is a spectacle that merits popularity.