Although it's termed a 'teaser' on social media, the promo is over two minutes long and is the first 'official' trailer for the Avengers: Age of Ultron due to release next summer.

The teaser indicates dark times ahead for the Avengers. According to Deadline, the sequel picks up with billionaire playboy Tony Stark (aka Iron Man played by Robert Downey Jr) trying to jumpstart a dormant peacekeeping program, which opens the window for Ultron's (James Spader) emergence.

According to the comic books, Ultron was created by Hank Pym (aka Ant-man), but since he's missing from the lineup of the Avengers, we wonder whether Tony Stark has actually created Ultron, since Ultron dons scraps of Iron Man armour.

The trailer shows signs of tension amongst the Avengers as it shows Thor grabbing Tony Stark by the throat and Iron Man (in his Hulkbuster suit that he especially designed in case of unexpected combat with his volatile ally) and the Hulk fighting it out in the middle of the city. Bruce Banner is shown wrapped in a blanket and collapsing in the snow, looking very vulnerable.

We are also introduced to two new characters in the trailer – Scarlet Witch (Elizabeth Olsen) and Quicksilver (Aaron Taylor-Johnson).

There are some morbid dialogues in the trailer such as Tony Stark saying, "It's the end, the end of the path I started us on," and Black Widow saying, "Nothing lasts forever."

Will this mark the end of Iron Man? Or the Hulk? Or Captain America, whose hand we see next to a broken Captain America shield?

What is the role of Andy Serkis in the movie, who we catch a glimpse of in the trailer?

The trailer's raised more questions than it answers and fans are now itching more than ever to watch the epic sequel: