How does Priestley make Inspector Goole's appearance and performance dramatically effective in An Inspector Calls?

Inspector Goole from the start is shrouded in mystery, and this continues throughout the play. His name makes it worryingly clear that what will happen is more an inquisition of souls than a normal detective investigation. It is through his methodical and painstaking detective work that each member of the family is exposed as contributing to the death of Eva Smith. When he says to the family: "It's the way I like to work. One person and one line of inquiry at a time. Otherwise there's a muddle", we become aware that he will work his way through each character. Goole remains impervious to any of the threats delivered by in particular Mr. Birling, and throughout the play it is clear that he is in charge and remains calm and does not get flustered. As Gerald's affair is revealed, Sheila begins to understand what is happening through Inspector Goole's approach: "No, he is giving us rope - so that we will hang ourselves." Throughout the play, Inspector Goole, in his relationships with the other characters, skillfully manipulates them through means of a bombardment of penetrating questions and hard startes which leaves them all feeling awkward and adds to the tension of the play.

How does Priestley make Inspector Goole's arrival ominous in "An Inspector Calls" (pages 8-12)?

When Edna announces the arrival of the inspector and mentions that he is from the police and that the reason for his calling is 'important' the reader/audience immediately senses that the inspector is not there to indulge in pleasantries. The abruptness of Mr. Birling's tone and the brevity of his conversation with Edna creates a mood of immediacy and urgency. His instruction to her to 'give us some more light' is an indication that some kind of mystery is to be brought to light. This creates an expectation that it could only be something bad, since firstly, the visitor is from the police and they hardly pay a courtesy visit at night to divulge good news and secondly, the inspector's name itself has an ominous ring to it - 'Gool' rhymes with ghoul which is an evil demon, supposedly one that feeds on humans.

Furthermore, the announcement unnerves Mr. Birling and although he responds with a humorous 'very' at Gerald's suggestion about an awkward situation if Eric should have been 'up to something', it is forced. This remark is made as Eric enters and he is ill at ease and speaks in a sharp tone. Furthermore, there is a slight verbal altercation between his father and he when he remarks that he does not believe that what has been said 'is very funny'. His father wants to know what the matter is with him and Eric curtly replies, 'Nothing.

The previously convivial atmosphere has now suddenly become quite tense, creating the expectation that, when the inspector actually enters, something bad is going to either happen or be said.

When the inspector finally enters after Edna's introduction, Priestly's description of him heightens the expectation further:

... he creates at once an impression of massiveness, solidity and purposefulness. He is a man in his fifties, dressed in a plain darkish suit of the period. He speaks carefully, weightily, and has a disconcerting habit of looking hard at the person he addresses before actually speaking.

This description immediately creates the impression that the inspector is there on an important and dire mission. The descriptors Priestly uses emphasize this fact: 'massiveness', 'solidity' and 'purposefulness'. 'Darkish' has an ominous ring to it. Added to this, is the description of how the inspector speaks - 'carefully, weightily.' Furthermore, the inspector unnerves his audience by the manner of his hard gaze when he addresses them individually.

The audience or reader, at this stage, cannot help but expect only the worst.