Answer:
A Thesis Statement.
Step-by-step explanation:
An Introductory paragraph is one of the crucial elements of an effective essay as it primarily functions to grab the readers' attention(through a hook or topic sentence), reveal the author's claim or point of view(through a thesis statement), and provide necessary background information that would help the readers' in understanding the narrator's message effectively.
The given introductory paragraph includes a hook('there was..fantasy'), background information('Robots..fingertips'), and they together set the tone but it misses a crucial element i.e. 'thesis statement' which would help in revealing the key point or claim to the readers. It offers a summarized version of the key argument of the essay that the author is going to deal with and since it is missing, the author's point of view is not established.