Agents of S.H.I.E.L.D viewers were treated to a cameo from Samuel L. Jackson as Nick Fury in the second episode on Tuesday night (October 1, 2013), though 34% of those who tuned in for the premiere missed the appearance.

Agents of SHIELDClark Gregg [center] as Agent Coulson in Agents of S.H.I.E.L.D.

ABC had hoped to avoid the annoying post-premiere ratings drop though it wasn't to be and Shield delivered 8.4 million viewers - still massive for 8pm, though a huge drop from last week.

Jackson's appearance was rumored though never officially confirmed by the network. His character arrived to give Agent Coulson (Clark Gregg) a serious talking to for damage to the agency's plane. "You know I have the authority to downgrade your ass to a Winnebago," he yelled.

Something of concern to ABC - on top of the decreased ratings - will be the critical reception for the second episode. Distinctly average. 

"The second episode of Agents of SHIELD wasn't as strong as the first and did point out some issues the show will need to work on as it develops," said IGN.

"There's still a tendency to over-reference the movies without expanding on their general mythology," said Den of Geek in a fair review, "...and while it was nice to see a character from Coulson's past it's impossible to shake the disappointment that with thousands of Marvel characters to choose from, they'd rather create a new one."

Watch the Agents of SHIELD trailer:

"Well, to be successful, this series needs to be accessible, it needs to flesh out its characters and develop its world, and it needs to find the right balance of heart, humor, and action," advised TV.com.

Elsewhere in ABC's ratings, new sitcom The Goldbergs suffered a 29 per cent trophy, while Trophy Wife fell 39 per cent.

Agents of S.H.I.E.L.D is based on the Marvel Comics organization, the Strategic Homeland Intervention, Enforcement and Logistics Division.