"Arrow" Season 2 has been action-packed in 2013. Several DC comics characters have checked-in, including (the first) Black Canary and Barry Allen aka The Flash. Stephen Amell's Oliver Queen faces three ghosts in the winter finale, but he is about to find out that one of them is very much alive and out to get him.

Spoiler alert: This feature recaps the highlights of Arrow Season 2 in 2013. Minor 2014 spoilers included, too. More action and suspense are expected in 2014 from this The CW superhero series.

John Diggle (David Ramsey) has reunited with ex-wife Lyla Michaels aka Harbinger (Audrey Marie Anderson) of A.R.G.U.S. (Advanced Research Group United Support). He rescues her in a Russian operation, during which Dig has been forced to work with his nemesis, Floyd Lawton aka Deadshot (Michael Rowe).

Olicity fans have seen several special moments between Oliver and Felicity (Emily Bett Rickards) in the first half of Arrow Season 2. Isabel Rochev (Summer Glau) ruins everything, but DC comics followers expect Oliver to still belong to Black Canary in the end.

The future Black Canary, Laurel Lance (Katie Cassidy) has gone from blaming the Arrow to blaming herself for Tommy's death. Toward the end of the first half of Arrow Season 2, she nearly loses her dad, Offier Quentin Lance (Paul Blackthorne). She has no idea her sister Sara (Caity Lotz) is alive, and has taken the identity of the Canary.

Deathstroke is seen as the show's ultimate villain this season. Slade Wilson has finally appeared in the present timeline, but he's no longer the same friend who'd die for Oliver Queen. The death of Shado (Celina Jade) has launched him into a vendetta against The Arrow himself.

Roy Harper is set to evolve in the next episode. He's been subjected to the same serum that has been injected to Deathstroke. When Arrow Season 2 returns in January 2014, Thea Queen (Willa Holland) will witness the changes in the emerging Arrow sidekick.

Sebastian Blood aka Brother Blood (Kevin Alejandro) is getting close to Laurel, who has become more vulnerable than ever since losing Tommy. When In Arrow Season 2, Episode 10, "Blast Radius," Laurel will be connecting some dots surrounding Blood's mercenary, Cyrus Gold.

Arrow Season 2, Episode 10, the winter premiere airs on Jan. 15 on The CW. "Firefly" fans will have more than Summer Glau next episode. Sean Maher is joining the cast as Mark Scheffer aka Shrapnel. He's out to get Brother Blood. Maher and Glau played siblings on the Firefly series.