Hey I remember reading a two part book. In the end first part the hero merges with a sentient star from going nova. His friend(an alien) along with the assassin that tries to kill him in the start also get sucked into this merger. All of them merge with the star and prevent it from going nova. In the end they create a sort of wormhole/bridge through space-time. In the second part it is about a vessel traveling through this bridge and face a threat from bat like aliens that pull passengers into the void while in hyper/metaspace and the protagonist is a little girl. There is a robot common to both these stories. Unfortunately I am unable to remember the name of this two titles and would greatly appreciate it if anyone can point me. Thanks in advance