I am at a point in my writing now where a new character is introduced and for the story to make sense the new character needs to know what the current characters did in the previous chapter. In most of the books I have read the author simply says something like: "Al explained to Ashley what had happened". Since the reader already knows the events of the previous chapter this seems the way to go so, but I wanted to know if there are other opinions on how this should or could be handled.
That is probably what I would do personally. I would elaborate a little by saying each point of interest that happened "And so Al recited to Ashley how they had first been sent by the agency to investigate but their paths had crossed that of a dragon and everything had gone wrong from there. "So, now you're stuck in this hell, just like me? Sucks to be you." Said Ashley. Al could only she believed her." Something like that to add a bit of interest to it but without making it longer than needed. I'm sure there are other techniques you can use like having another character speak to her offscreen or simply make some sort of transition where they set up camp and she's all up to speed.
Hard to say without knowing more, but you could either have a conversation between two characters along the lines of, "Hey, Ashley's coming tomorrow, too." "What? Why?" "I told her what happened and she had some good suggestions. I think she'll be helpful." Obviously, better than that and more illuminating. But something along those lines. However, it is possible you might not even need to explain. I don't know if you watched Breaking Bad, but in the last season, there was a scene where it was obvious a character had been informed about what had transpired, even though we didn't see it. Basically, a DEA agent was dealing with someone involved with drugs. Another person involved with producing the drugs had created this set-up, where he was going to blackmail this DEA agent. No other agents knew what was going on or that any of this had happened, or even that the DEA agent had figured out who this big-time drug producer was. But in a scene where they're interrogating someone, this other agent, who we've met before, was there. We never saw him clued in about what was going on, but the viewers knew he knew.
Consider keeping the new character off balance. He or she arrives expecting to be briefed on the current sit, but before that can happen, all hell breaks loose. New character has to simply react, use his or her wits and skills. By the time anyone can explain, Newly has figured most of it out anyway.
Al settled into his chair. "So. Long story. When we went to the DMV, there was this vampire driving instructor..." Ashley dumped her backpack on the table. "Yeah, Joe told me the whole thing. Hang on, I need a beer." Al blinked as he watched her retreat. Hmph. Women. No appreciation for a good story.
I think just saying that the character explained it would be a fine way to do it. Alternatively I often let my characters describe a briefing in their own words, lends a bit of characterization on how they view things. Either way serves its purpose and moves the story along.
if you character developement is strong enough, you should be able to have them explain a few of the key details instead of watering it down to "Al explained to Ashley what had happened" like deathandgrim said, it is also a good oppurtunity to stregnthen your characters.