diff --git a/lib/bcoin/chain.js b/lib/bcoin/chain.js
index 6a14e270..3411d112 100644
--- a/lib/bcoin/chain.js
+++ b/lib/bcoin/chain.js
@@ -768,7 +768,7 @@ Chain.prototype._findFork = function _findFork(fork, longer, callback) {
       if (longer.height <= fork.height)
         return done();
 
-      self.db.get(longer.prevBlock, function(err, entry) {
+      longer.getPrevious(function(err, entry) {
         if (err)
           return callback(err);
 
@@ -785,7 +785,7 @@ Chain.prototype._findFork = function _findFork(fork, longer, callback) {
       if (fork.hash === longer.hash)
         return callback(null, fork);
 
-      self.db.get(fork.prevBlock, function(err, entry) {
+      fork.getPrevious(function(err, entry) {
         if (err)
           return callback(err);
 
@@ -814,7 +814,7 @@ Chain.prototype._reorganize = function _reorganize(entry, callback) {
       var entries = [];
 
       (function collect(entry) {
-        self.db.get(entry.prevBlock, function(err, entry) {
+        entry.getPrevious(function(err, entry) {
           if (err)
             return callback(err);
 
@@ -871,7 +871,7 @@ Chain.prototype._reorganize = function _reorganize(entry, callback) {
       var entries = [];
 
       (function collect(entry) {
-        self.db.get(entry.prevBlock, function(err, entry) {
+        entry.getPrevious(function(err, entry) {
           if (err)
             return callback(err);
 
@@ -1332,8 +1332,6 @@ Chain.prototype.add = function add(initial, peer, callback, force) {
           if (entry.chainwork.cmp(self.tip.chainwork) <= 0)
             return done();
 
-          // Add entry if we do not have it.
-
           // Update the block height
           block.height = entry.height;
           block.txs.forEach(function(tx) {
@@ -1706,7 +1704,7 @@ Chain.prototype.getLocator = function getLocator(start, callback, force) {
     return callback(null, top);
   }
 
-  getTop(function(err, top) {
+  return getTop(function(err, top) {
     if (err) {
       unlock();
       return callback(err);
@@ -1808,7 +1806,7 @@ Chain.prototype.getTargetAsync = function getTarget(last, block, callback) {
         if (last.height > 0
           && last.height % network.powDiffInterval !== 0
           && last.bits === powLimit) {
-          return self.db.get(last.prevBlock, next);
+          return last.getPrevious(next);
         }
 
         return callback(null, last.bits);
@@ -1829,7 +1827,7 @@ Chain.prototype.getTargetAsync = function getTarget(last, block, callback) {
     if (i >= network.powDiffInterval)
       return callback(null, self.retarget(last, first));
 
-    self.db.get(first.prevBlock, next);
+    first.getPrevious(next);
   })(null, last);
 };
 
@@ -1928,7 +1926,7 @@ Chain.prototype.getState = function getState(prev, block, id, callback) {
     var bits = entry.version & constants.versionbits.TOP_MASK;
     var topBits = constants.versionbits.TOP_BITS;
     var mask = 1 << deployment.bit;
-    return (bits === topBits) && (entry.version & mask) !== 0;
+    return bits === topBits && (entry.version & mask) !== 0;
   }
 
   (function walk(err, entry) {
@@ -1999,7 +1997,7 @@ Chain.prototype.getState = function getState(prev, block, id, callback) {
             if (condition(entry))
               count++;
 
-            return self.db.get(entry.prevBlock, next);
+            return entry.getPrevious(next);
           })(null, entry);
 
           function doneCounting(err) {
diff --git a/lib/bcoin/chainblock.js b/lib/bcoin/chainblock.js
index 1ff5b527..8285adf9 100644
--- a/lib/bcoin/chainblock.js
+++ b/lib/bcoin/chainblock.js
@@ -82,7 +82,7 @@ ChainBlock.prototype.toRaw = function toRaw() {
   utils.writeU32(res, this.bits, 72);
   utils.writeU32(res, this.nonce, 76);
   utils.writeU32(res, this.height, 80);
-  utils.copy(new Buffer(this.chainwork.toArray('be', 32)), res, 84);
+  utils.copy(new Buffer(this.chainwork.toArray('le', 32)), res, 84);
 
   return res;
 };
@@ -97,7 +97,7 @@ ChainBlock.fromRaw = function fromRaw(chain, p) {
     bits: utils.readU32(p, 72),
     nonce: utils.readU32(p, 76),
     height: utils.readU32(p, 80),
-    chainwork: new bn(p.slice(84, 116), 'be')
+    chainwork: new bn(p.slice(84, 116), 'le')
   });
 };
 
@@ -119,7 +119,7 @@ ChainBlock.prototype.getMedianTimeAsync = function getMedianTime(callback) {
     median[i] = entry.ts;
     i++;
 
-    self.chain.db.get(entry.prevBlock, next);
+    entry.getPrevious(next);
   })(null, this);
 };
 
@@ -149,7 +149,7 @@ ChainBlock.prototype.isSuperMajorityAsync = function isSuperMajority(version, re
 
     i++;
 
-    self.chain.db.get(entry.prevBlock, next);
+    entry.getPrevious(next);
   })(null, this);
 };
 
@@ -225,7 +225,7 @@ ChainBlock.prototype.getAncestors = function getAncestors(max, callback) {
     if (previous.length >= max)
       return callback(null, previous);
 
-    self.chain.db.get(entry.prevBlock, next);
+    entry.getPrevious(next);
   })(null, entry);
 };
 
@@ -233,19 +233,65 @@ ChainBlock.prototype.free = function free() {
   this.previous.length = 0;
 };
 
+ChainBlock.prototype.isMainChain = function isMainChain(callback) {
+  var self = this;
+  return this.chain.db.getHash(this.height, function(err, hash) {
+    if (err)
+      return callback(err);
+
+    if (!hash)
+      return callback(null, false);
+
+    return callback(null, self.hash === hash);
+  });
+};
+
 ChainBlock.prototype.getAncestorByHeight = function getAncestorByHeight(height, callback) {
+  assert(height >= 0);
   assert(height <= this.height);
-  return this.getAncestor(this.height - height, callback);
+  return this.getAncestor(this.height - height, function(err, entry) {
+    if (err)
+      return callback(err);
+
+    if (!entry)
+      return callback();
+
+    assert(entry.height === height);
+
+    return callback(null, entry);
+  });
 };
 
 ChainBlock.prototype.getAncestor = function getAncestor(index, callback) {
+  assert(index >= 0);
   return this.getAncestors(index + 1, function(err, previous) {
     if (err)
       return callback(err);
+
+    if (previous.length !== index + 1)
+      return callback();
+
     return callback(null, previous[previous.length - 1]);
   });
 };
 
+ChainBlock.prototype.getPrevious = function getPrevious(callback) {
+  return this.chain.db.get(this.prevBlock, callback);
+};
+
+ChainBlock.prototype.getNext = function getNext(callback) {
+  var self = this;
+  return this.chain.db.getNextHash(this.hash, function(err, hash) {
+    if (err)
+      return callback(err);
+
+    if (!hash)
+      return callback();
+
+    return self.chain.db.get(hash, callback);
+  });
+};
+
 ChainBlock.prototype.getMedianTime = function getMedianTime(previous) {
   var entry = this;
   var median = [];
@@ -300,6 +346,18 @@ ChainBlock.prototype.getMedianTimeAsync = function getMedianTimeAsync(callback)
   });
 };
 
+ChainBlock.prototype.inspect = function inspect() {
+  var copy = new ChainBlock(this.chain, this, null);
+  copy.__proto__ = null;
+  copy.hash = utils.revHex(copy.hash);
+  copy.prevBlock = utils.revHex(copy.prevBlock);
+  copy.merkleRoot = utils.revHex(copy.merkleRoot);
+  copy.chainwork = copy.chainwork.toString(10);
+  delete copy.chain;
+  copy.previous = this.previous.length;
+  return copy;
+};
+
 /**
  * Expose
  */
diff --git a/lib/bcoin/utils.js b/lib/bcoin/utils.js
index e43288eb..16342f96 100644
--- a/lib/bcoin/utils.js
+++ b/lib/bcoin/utils.js
@@ -1673,8 +1673,8 @@ utils.getMerkleRoot = function getMerkleRoot(leaves) {
 
 utils.getMerkleBranch = function getMerkleBranch(index, leaves) {
   var tree = utils.buildMerkleTree(leaves);
+  var size = leaves.length;
   var branch = [];
-  var size = this.totalTX;
   var j = 0;
   var i;