Tim Drake has been through a number of serious changes over the past decade. He has adopted three different monikers, came out as bisexual, and even died at one point. Despite all of these changes, the character has not had a solo series since 2011. Prior to the New 52, Tim was the only Robin to have a solo title, and his popularity ensured that that title lasted over 100 issues. His following series, Red Robin, depicted Tim's growth beyond the role of Robin, and adopting the new mantle proved to be a milestone for the character. Like Dick Grayson's transformation into Nightwing, this symbolized Drake's transition out of the shadow of the Batman. This transition, however, led the character down a dark path that eventually proves that he was the ultimate detective.
Following the death of Batman in Final Crisis and the events of Battle For The Cowl, Dick Grayson took on the role of Batman, and chose Damian Wayne as his partner, leaving Tim to choose his own path. Infuriated by being replaced and losing his purpose, Tim left Wayne Manor convinced that Bruce was still alive, and began to search for his mentor under the new identity of Red Robin.
The mantle of Red Robin, however, comes with a tainted legacy. The identity originated in Kingdom Come (by Mark Waid and Alex Ross), where an older version of Dick Grayson is seen wearing the suit. In the mainstream timeline, both Jason Todd and Ulysses Armstrong have worn the suit, although Armstrong used it to torment Robin. Tim donned the mantle (and its tarnished reputation) in an effort to dissociate himself from the Bat-Family, allowing him to cross lines he would not have been able to as Robin.
During his search around the world, Tim was trailed by members of the League of Assassins. After deducing their identities, he was contacted by Ra's Al Ghul, who also believed that Bruce was alive. drake begrudgingly formed an alliance with Ra's, and the assassins who were following him were tasked with protecting him. Eventually, Tim's journey led him to a prehistoric painting of the Batman logo etched into the walls of a cave, proving to Tim that Bruce was still alive somewhere.
The story continued with the members of the League of Assassins being terminated by the Council of Spiders. Tim is then tasked by the League with finding and stopping the Council, which he is only able to do after accessing the League's global computer system and destroying it.
The first arc of the series concluded with Tim confronting Ra's Al Ghul, after tracking him down through League shell companies and real estate holdings that he accessed on the computer. He thwarts Ra's plans to bankrupt Wayne Enterprises with the help of Hush, who was disguised as Bruce Wayne. Showing his respect to Tim, Ra's calls him "detective", a name that he had previously reserved for Batman. Although Tim fights Ra's and is nearly killed, he still feels a sense of peace with the realization that Bruce was alive and Ra's had been thwarted.
The first run of Red Robin cemented Tim as a solo character who had grown out of the shadow of the Batman and become equal to Dick, proving himself by earning the respect of one of Batman's greatest foes. The premise of the story was based on Tim's detective work, and willingness to do things that hid mentor would not, such as working with villains to achieve his end goal. For many years since, the character has been lost, with no clear long-term direction. It seems as though this may change soon as he expected to play a large role in the upcoming Dark Crisis: Young Justice as well as the main Batman title. All in all, the path that led Tim to finding Batman, and stopping Ra's proved that he was at one time one of DC's best detectives.
