This farce concerns the shocking methods by which Lupin attempts to steal the Penultimate Night, and how he attempts to match wits with Holmes. A certain detective looks to thwart Lupin in her own way, and so appears in a most unexpected location.
In that case—
...في تلك الحالة
In dem Fall …
Dans ce cas…
Bene, dunque!
Nesse caso—
Ну а раз так…